Let me know if you or anyone else figures it out for that matter. I tried modifying a few different values just to see if I did something wrong but I wasn't able to see any changes. I did note down everything that was already unlocked and their prices and went from there but I wasn't able to get the "crate cars" to do anything different.
It would be helpful to describe what the purchase prices for these vehicles become as a reference, or better yet use a screen recording app to post a video of it being done. But regardless if it works for someone please by all means help me out because I am trying to max out a few T5 vehicles that I have already. Also, the cheat that gives gold / cash / keys still works just fine, its just hard to get 5 star vehicles lol...