ukcrazy99

By car packs, do you mean standalone cars?  If yes, how many standalone cars do you have in your game?  You might be past the allowed amount of standalone vehicles that can be in the game.   If this is the case, please use my gameconfig which was modified to allocate a lot of extra standalone cars. 
https://www.dropbox.com/s/dcao58yvfbtqedo/gameconfig.xml?dl=0
If standalone cars are not the issue, please upload your meta and carvar for these DLC packs.

I think that is it.
Vehicles.meta and carvariations.meta are very picky - If one little thing is missing or wrong, boom, game crashes. Put in your original carvariations.meta and vehicles.meta, and search on youtube on how to install those 2 files. A video should cover with you how sensitive they are, and help you notice if anything is missing that could be causing the crash. 
Try to do that. A skipped line, a missing > or something small like that could be causing it, so just double check the author has everything right.

Very excited, I can't wait to play and explore 0.2!