I just did another to test it out. I installed this mod.

https://www.gta5-mods.com/vehicles/2015-lexus-rcf-add-on-rocketbunny

It only comes as an ADDON so I extracted the files from the dlc and applied to handling,vehicle meta files, along with the ytd,yft files to replace felon2. The car spawns perfect and dials work also.

Id like to mention that I'm also using this mod that may have an affect on this.
https://www.gta5-mods.com/misc/missing-speedometer-solution-in-replace-car-modes

So I downloaded this mod.
https://www.gta5-mods.com/vehicles/2009-bmw-m5-e60-add-on-yca-y97y
It only comes as an ADDON, but I wanted to replace it with schafter3. I extracted the vehicle,handling meta files from the dlc.rpf and swapped over the info. I replaced the schafter3 ytd,yft,_hi.yft files.
I spawned the car (which shows up fine) and for the life of me I cant seem to get the dials to line up perfectly. I see them but they are out of place.
I know its got something to do with changing the dashboard vdt files and/or adding the dial textures but I cant figure it out. Anyone got tips or able to try it to see if it works for you? Thanks.

@kianshea2 One more thing as I recall. If it only comes as a replace, you could copy the meta files from another car you feel similar, and simply edit those files and change the name files to the dlc car.

Also, try to work on one car at a time. I know its time consuming but that way you can easily back track mistakes to fix any loading errors. Cheers!

Ive figured out how to add more clothing textures to peds. But I can't seem to make them spawn with the other outfits. I used meta toolkit to edit the ymt files and then added the textures to the ytd. Ive compared the ymt file and ytd file to other peds that spawn with multiple clothing setups and I cant seem to pinpoint what exactly I'm missing. Anything tips will help.

So if the car mod that you want to install comes ONLY as a replace, you wont have the handling.meta and vehicle.metas. Most likely I would think the author would swap the car with something comparable to power, spec, car type, etc. But to answer your question tho, there wont be a customized handling.meta to replace. It will handle just like the car you replaced. For this instance, I recommend changing the <HANDLINGID> in the vehicle.meta to something you think would match.

So for example: I simple change the way the NINEF handles by changing it to SULTAN.

<Item>
<modelName>ninef</modelName>
<txdName>ninef</txdName>
<handlingId>SULTAN</handlingId>
<gameName>NINEF</gameName>
<vehicleMakeName>OBEY</vehicleMakeName>

If the car comes as a addon, but you want to replace instead. You simply add the car mod file into your dlcpacks, and extract all the files you need. Then you pick a car you want to replace it with and start changing all the files. GOod luck man!

As I said, the replacement is just so I can see AI driving it around town in stock form while my addon version will come with all the mods etc.

Can you have both of the same car? I would think so since the files are completely different. I dont care to add (edit mods) into traffic car versions but for my personal addon cars I want the mods, which is why I want to have both. So I add the file to dlcpacks and dlclist for the addon version while also completing the replacement steps. Just wondering if this is a good idea. Thanks!

Basically when I reach a certain distance from my replace peds, their clothing completely changes or part of them are gone. Just like how vehicles parts disappear too when you get a certain distance as well. I know how to fix the cars but where would I go to fix the peds. Thanks!

It can be done. Just be sure to replace the files for that vehicle in the right folder(s). Some will be trial and error. Then you'll have to work around mods to get them to work. Also dont forget handling and vehicle.meta. you may have to edit those to get the vehicle to run well. Good luck! I love doing this cause it can be very satisfying when you complete a car!

This can be done easily. You have to be sure you're changing the ytd,yft, and _hi.yft files in the right places. I recommend using the search function to find out how many times its been patched. Most of the time it can be replaced successfully by changing the files in the latest patch, IE patchday3ng, etc. Keep in mind that you may have to deal with texture issues and work around mods, handling and vehicle metas.