The fact that you and your wife, as intelligent adults, don't recognize the complete 200% utter idiocy of paying someone for a car and having the title in both names is clearly an indication of something fucked up.
This would be like buying a house, with 150k cash, from a bank. But the bank is like, "hey dude lets keep the title in both our names because I want to still own the house you just paid for IN FULL, sound cool?". Then you say yes. Then the bank basically says "hey dude thanks for paying me 150k for the house. Thing is, with the title in both our names I still own it and even though I appreciate the money and all I think I'm gonna sell it again to someone smart enough to not keep me a joint owner".
Seriously. I can only pray you're trolling, because the seriousness of the equal levels of stupidity from the minor and the clear lack of common sense of general practice involving migrating ownership of assets from both you and your wife HAS to be a joke, and cannot be real.