I purchased a used car 7 days ago and so did my girlfriend. The problem is we were only suppose to buy one car. Now I need to get out of my contract. I noticed that when I filled out the credit apllication the sales person told me to leave a section blank(where it asks what my monthly income is. Well I did but they approved me and filled in the blank without my permission so they lied on my credit application so I could get approve. Can I use that against them so I can return the used car. By the way this is in California

I don't think you can return the car. You can mention to the dealer about the income box being filled in by them but you would have had to give them some sort of an idea of what number to fill in.

Basically no, you signed the bottom of the application leaving it blank, so there is no way to prove first that they did not fill this in and then you signed it.

Also even if you could prove it, it does not make the sales contract invalid.

But what the heck, it is worth a try, if you are willing to perhaps loose your down payment they may do it, to not have to hassle with you.