@Guyconfident
Have you added this line:

<Item>dlcpacks:\EMF\</Item>

to your 'dlclist.xml' here:

...\mods\update\update.rpf\common\data\dlclist.xml

Your 'dlclist.xml' should look somewhat like this afterwards

<item>dlcpacks:\LA_ROADS\</item> <Item>dlcpacks:\addoncars\</Item> <Item>dlcpacks:\baba0rum\</Item> <Item>dlcpacks:\EMF\</Item> </Paths> </SMandatoryPacksData>

^That is the correct format (ie line placed above the '</Paths>' & '</SMandatoryPacksData>' lines)

After that it's just a matter of putting the replace vehicle's '.ytd' & '.yft' into this folder:

...\mods\update\x64\dlcpacks\EMF\dlc.rpf\x64\vehicles.rpf

so it looks like this:

& then any tuning parts they have into this one:

...\mods\update\x64\dlcpacks\EMF\dlc.rpf\x64\vehicle_mods.rpf

Note: You place just the individual vehicle modifications ('blade_hood_1.yft' etc for example) into the 'vehicle_mods.rpf'. Do NOT put the vehicles '_mods.rpf' (say 'blade_mods.rpf') archive into there. If done correctly you will end up with lots of different vehicle's modifications all in the same folder like this:

The only other thing to look out for is you can't delete the 'vehshare.ytd' in:

...\mods\update\x64\dlcpacks\EMF\dlc.rpf\x64\vehshare.rpf

or the game will crash.

Note: You can save yourself some hassle & ensure that all of the textures in 'vehshare.ytd' display correctly in-game if you make sure all of the 'vehshare.ytd's that you have installed (throughout your entire 'mods' folder. Not just the 'EMF' folder structure) are the same file with the exact same textures in them.
If you have modded 'vehshare.ytd' in the past then all you would do is grab a copy of it & place it here:

...\mods\update\x64\dlcpacks\EMF\dlc.rpf\x64\vehshare.rpf\vehshare.ytd

overwriting the one that comes with the EMF mod.

You can then use Ctrl+F3 in OpenIV to search for 'vehshare.ytd' & make sure they are ALL the same file. If not, overwrite & replace them all with your modded 'vehshare.ytd' of choice.
Be careful as certain mods require their own 'vehshare.ytd' that is different to your prefered modded one. In that case you would want to import any different textures into your modded one (careful not to overwrite any (of the same name) you want to keep) so that it has all of the textures you need for everything. You then replace all the 'vehshare.ytd's in your 'mods' folder structure with your new super 'has everything you need in it' 'vehshare.ytd'.
If you don't do this, it won't break your game, you just run the risk that some things (alloy wheels are a good example) may show up missing their textures/weird colours etc.