@meimeiriver I'm looking in the xml now and it seems like it may have copied wrong because the hevo thing looks right now. But I just looked over it so I'm gonna try to fire up the game and see what happens.

@meimeiriver I did not know that was a thing. You have just saved me so much time. Thank you so much! Does the validator happen to fix those slashes? It might take me a while to fix all of those. Also, does the slashes with the name of the addon need to match the slash in </Item>?

@meimeiriver I copied and pasted the names exactly how they said from the readme and I used the package Installer on the ones that said they needed it. I also just noticed that it looks like a few of the package installer ones actually put it at the top which could be the problem here. I'm relatively new to modding specifically with cars in this game so my apologies if the mistake was more obvious than I thought it was.

<?xml version="1.0" encoding="UTF-8"?>
<SMandatoryPacksData>
<Paths>
<Item>dlcpacks:\hs</Item>
<Item>dlcpacks:\lanex400</Item>
<Item>dlcpacks:\EK9</Item>
<Item>platform:/dlcPacks/mpBeach/</Item>
<Item>platform:/dlcPacks/mpBusiness/</Item>
<Item>platform:/dlcPacks/mpChristmas/</Item>
<Item>platform:/dlcPacks/mpValentines/</Item>
<Item>platform:/dlcPacks/mpBusiness2/</Item>
<Item>platform:/dlcPacks/mpHipster/</Item>
<Item>platform:/dlcPacks/mpIndependence/</Item>
<Item>platform:/dlcPacks/mpPilot/</Item>
<Item>platform:/dlcPacks/spUpgrade/</Item>
<Item>platform:/dlcPacks/mpLTS/</Item>
<Item>dlcpacks:/mpheist/</Item>
<Item>dlcpacks:/mppatchesng/</Item>
<Item>dlcpacks:/patchday1ng/</Item>
<Item>dlcpacks:/patchday2ng/</Item>
<Item>dlcpacks:/mpchristmas2/</Item>
<Item>dlcpacks:/patchday2bng/</Item>
<Item>dlcpacks:/patchday3ng/</Item>
<Item>dlcpacks:/patchday4ng/</Item>
<Item>dlcpacks:/mpluxe/</Item>
<Item>dlcpacks:/patchday5ng/</Item>
<Item>dlcpacks:/mpluxe2/</Item>
<Item>dlcpacks:/patchday6ng/</Item>
<Item>dlcpacks:/mpreplay/</Item>
<Item>dlcpacks:/patchday7ng/</Item>
<Item>dlcpacks:/mplowrider/</Item>
<Item>dlcpacks:/mphalloween/</Item>
<Item>dlcpacks:/patchday8ng/</Item>
<Item>dlcpacks:/mpapartment/</Item>
<item>dlcpacks:/mpxmas_604490/</item>
<Item>dlcpacks:/mplowrider2/</Item>
<Item>dlcpacks:/mpjanuary2016/</Item>
<Item>dlcpacks:/mpvalentines2/</Item>
<Item>dlcpacks:/patchday9ng/</Item>
<Item>dlcpacks:/mpexecutive/</Item>
<Item>dlcpacks:/patchday10ng/</Item>
<Item>dlcpacks:/mpstunt/</Item>
<Item>dlcpacks:/patchday11ng/</Item>
<Item>dlcpacks:/mpimportexport/</Item>
<Item>dlcpacks:/mpbiker/</Item>
<Item>dlcpacks:/patchday12ng/</Item>
<Item>dlcpacks:/patchday13ng/</Item>
<Item>dlcpacks:/mpspecialraces/</Item>
<Item>dlcpacks:/mpgunrunning/</Item>
<Item>dlcpacks:/mpairraces/</Item>
<Item>dlcpacks:/mpsmuggler/</Item>
<Item>dlcpacks:/mpchristmas2017/</Item>
<Item>dlcpacks:/mpassault/</Item>
<Item>dlcpacks:/mpbattle/</Item>
<Item>dlcpacks:/patchday14ng/</Item>
<Item>dlcpacks:/patchday15ng/</Item>
<Item>dlcpacks:/patchday16ng/</Item>
<Item>dlcpacks:/patchday17ng/</Item>
<Item>dlcpacks:/patchday18ng/</Item>
<Item>dlcpacks:/patchday19ng/</Item>
<Item>dlcpacks:/patchday20ng/</Item>
<Item>dlcpacks:/mpchristmas2018/</Item>
<Item>dlcpacks:/patchday21ng/</Item>
<Item>dlcpacks:/mpvinewood/</Item>
<Item>dlcpacks:/patchday22ng/</Item>
<Item>dlcpacks:/mpheist3/</Item>
<Item>dlcpacks:\16challenger</Item>
<Item>dlcpacks:\69charger</Item>
<Item>dlcpacks:\16charger</Item>
<Item>dlcpacks:\stingray66</Item>
<Item>dlcpacks:\chargerf8</Item>
<Item>dlcpacks:\nsexrb</Item>
<Item>dlcpacks:\skylinec110</Item>
<Item>dlcpacks:\ngtr35nismo17</Item>
<item>dlcpacks:\senna</item>
<Item>dlcpacks:\viper</Item>
<Item>dlcpacks:\c7</Item>
<Item>dlcpacks:\i8</Item>
<Item>dlcpacks:\NC1</Item>
<Item>dlcpacks:\rmodlp770</Item>
<Item>dlcpacks:\rmodm4</Item>
<Item>dlcpacks:\fxxk</Item>
<Item>dlcpacks:\rmodmustang</Item>
<Item>dlcpacks:\720s</Item>
<Item>dlcpacks:\rs6</Item>
<Item>dlcpacks:\regera</Item>
<Item>dlcpacks:\rrphantom</Item>
<Item>dlcpacks:\cx75</Item>
<Item>dlcpacks:\ast</Item>
<Item>dlcpacks:\iverson</Item>
<Item>dlcpacks:\fastback</Item>
<Item>dlcpacks:\camaro_ss</Item>
<Item>dlcpacks:\tkmod</Item>
<item>dlcpacks:\focusrs</item>
<item>dlcpacks:\mxpan</item>
<item>dlcpacks:\amggtr</item>
<Item>dlcpacks:/amggtc/</Item>
<Item>dlcpacks:/wmotors/</Item>
<Item>dlcpacks:/19GT500/</Item>
<Item>dlcpacks:/chiron/</Item>
<Item>dlcpacks:/gt63samg/</Item>
<Item>dlcpacks:\350zrb</Item>
<Item>dlcpacks:\Vulcan</Item>
<Item>dlcpacks:\teslamodels</Item>
<Item>dlcpacks:\Firebird</Item>
<Item>dlcpacks:\amcj-3</Item>
<Item>dlcpacks:\c8</Item>
<Item>dlcpacks:\Alston</Item>
<Item>dlcpacks:\hevo</Item>
<Item>dlcpacks:/custom_maps/</Item>
<Item>dlcpacks:/mb_addons/</Item>
<item>dlcpacks:\reventon</item>
<Item>dlcpacks:/wov/</Item>
<Item>dlcpacks:/wov_expansion/</Item>
dlcpacks:\drag
<Item>dlcpacks:\tf_bike</Item>
<Item>dlcpacks:\hotrod2</Item>
<Item>dlcpacks:/redbullx1/</Item>
<Item>dlcpacks:/redbullx2/</Item>
<Item>dlcpacks:/r8race/</Item>
<Item>dlcpacks:\bmws</Item>
<Item>dlcpacks:\c7r</Item>
<Item>dlcpacks:\lambohgt3</Item>
<Item>dlcpacks:\fgt3</Item>
<Item>dlcpacks:\fgt3</Item>
<Item>dlcpacks:\rmodsian</Item>
<Item>dlcpacks:\rmodgtr</Item>
<Item>dlcpacks:\rmp4</Item>
<Item>dlcpacks:\jgtc34</Item>
<Item>dlcpacks:\pragar1</Item>
<Item>dlcpacks:\fordcapri</Item>
<Item>dlcpacks:\imsa90</Item>
<Item>dlcpacks:\fusionnas</Item>
<Item>dlcpacks:\audir8lms2</Item>
<Item>dlcpacks:\zondar</Item>
<Item>dlcpacks:\rmodmustang</Item>
<Item>dlcpacks:\LaFerrari2015</Item>
<item>dlcpacks:\r8ppi</item>
<item>dlcpacks:\mig</item>
<item>dlcpacks:\ssc</item>
<item>dlcpacks:\supersport</item>
<item>dlcpacks:\gto</item>
<Item>dlcpacks:\aventadors</Item>
<Item>dlcpacks:/a80/</Item>
<Item>dlcpacks:\r1</Item>
<item>dlcpacks:\fordh</item>
<Item>dlcpacks:\q820</Item>
<Item>dlcpacks:\sr650fly</Item>
<Item>dlcpacks:\yacht2</Item>
<item>dlcpacks:\mqgts</item>
<item>dlcpacks:\levante</item>
<item>dlcpacks:\m2</item>
<item>dlcpacks:\ghis2</item>
<Item>dlcpacks:\mgrantur2010</Item>
<Item>dlcpacks:\mlmansory</Item>
<Item>dlcpacks:\mc12</Item>
<Item>dlcpacks:\gt1</Item>
<item>dlcpacks:\s30</item>
<item>dlcpacks:\na1</item>
<Item>dlcpacks:\skyline</Item>
<item>dlcpacks:\smg</item>
<Item>dlcpacks:\911turbos</Item>
<Item>dlcpacks:\srt8</Item>
<item>dlcpacks:\918</item>
<item>dlcpacks:\avj</item>
<Item>dlcpacks:\svj63</Item>
<Item>dlcpacks:\camry18</Item>
<Item>dlcpacks:\ts1</Item>
<Item>dlcpacks:\MC</Item>
<Item>dlcpacks:\ep9</Item>
<item>dlcpacks:\675ltsp</item>
<item>dlcpacks:\lambo</item>
<Item>dlcpacks:\giulia</Item>
<Item>dlcpacks:\lc500</Item>
<Item>dlcpacks:\lfa</Item>
<Item>dlcpacks:\m1</Item>
<Item>dlcpacks:\raptor</Item>
<Item>dlcpacks:\bmwz4</Item>
<Item>dlcpacks:\Stelvio</Item>
<Item>dlcpacks:\Roadster</Item>
<Item>dlcpacks:\Divo</Item>
<Item>dlcpacks:\ap2</Item>
<Item>dlcpacks:\911tbs</Item>
<item>dlcpacks:\911R</item>
<Item>dlcpacks:\panamera17turbo</Item>
<Item>dlcpacks:\hondacivictr</Item>
<Item>dlcpacks\tamo</Item>
</Paths>
</SMandatoryPacksData>

@meimeiriver The one that I edited? I did not know that could happen so that very well may be it. Give me a minute or two and I'll pull it up. Thanks!

@meimeiriver Thank you for the fast response! I'm not entirely sure how it works but what happens is specifically when I have OpenIV.asi installed in my directory, I cannot spawn any of the dlc vehicles. It just tells me "Invalid Model" or "Vehicle Does Not Exist". But when I uninstall OpenIV.asi I can spawn them. But either way, I am still not able to spawn addon vehicles with or without it. Edit: I just double checked to make sure and I launched my game, I can use all dlcs from the very first one added to the game up to the "Festive Surprise" dlc. Nothing after that dlc is available. Still no addon vehicles either.

@meimeiriver I have my mods folder and the update + x64 files copied into it and those are the ones that I modified. Sorry, I'm new to this sort of thing and I guess I didn't explain it very well. The update.rpf that I modified is inside the update folder that is inside my mods folder. In OpenIV the mods folder appears purple, so I assume that means it at least knows it's there. The dlclist I changed is inside of my mods folder under that same path you listed 'Grand Theft Auto V\mods\update\update.rpf\common\data'. I just checked again and the addon cars are listed in that dlclist.xml inside the altered update folder. I have also put the addon vehicles required files in Grand Theft Auto V\mods\update\x64\dlcpacks. My apologies for not writing anything useful the first time yet writing so much at the same time. Thank you for the response anyways

I've been having this issue with installing addon vehicles. I've searched up solutions but I couldn't find any so I just decided to post here. I have downloaded https://www.gta5-mods.com/misc/gta-5-gameconfig-300-cars and I also have the OpenIV asi loader and OpenIV.asi installed. I use https://www.gta5-mods.com/scripts/add-on-vehicle-spawner to spawn in these addon vehicles, it worked one time when I launched the game and I haven't been able to see the addon vehicles in that menu since. But I have also tried using spawn names through simple trainer and menyoo, but it either says "Invalid Model" or "Vehicle Does Not Exist". I've been trying at this for almost 3 days now and I have not had any luck at all and I noticed that when I have OpenIV.asi installed, I am also not able to spawn dlc vehicles (yes, I have the dlc unlocker and everything). When I removed OpenIV.asi I was then able to spawn the dlc vehicles, but still no addon vehicles unfortunately. I have my addon vehicles installed correctly from what I've seen according to the many, many videos I've watched. I said this earlier but I had it working one time but I don't know what changed and I can't seem to replicate it. Removing all my scripts did nothing either. I have a reason to believe that the OpenIV.asi thing that allows support for custom rpfs and the mod folder has something to do with this issue. I followed all the readme files when I was installing these addon vehicles, right now not even one out of any of these vehicles pop up in the addon vehicle spawner. Just to be clear, I do not have any replace vehicles, only addon vehicles. Anyways, that's all the issues and details I could think of off the top of my head while writing this. Any help would be greatly appreciated, Thank you.