On a side note...I'm almost 23 too...Hopefully I have no problem being financed like you did! I don't have any negative record on my credit. We will see!
You make less than 14k a year but want a car that is going to end up at over 40k after fees and negative equity? That just doesn't make sense and is far reaching, not trying to be rude but you need to be realistic. Yes your boyfriend may make 4400 a month but do you really want to depend on someone else to take care of something so large? What if you two break things off? There are plenty of nice cars that are far less.
Even with your and your boyfriend's combined income there should not be a $40k car there. I understand the cars are nice but that is an awful lot to take on.