that is true, traditionally the girls parents pay for most if not all of their daughters wedding. but i'm just busting your balls. listen, in my eyes you have 2 choices, you either do what she says, and you put the car off on the side of the house until you can fix it and you help her out, or, put this relationship to the test before you tie the knot and end up screwed, and say honey, i dont give a :q:q:q:q if the wedding is this close, my car needs work and i am taking what little money i have tucked away and i am fixing the god damn car and if you have a problem with it, lets solve it right now. test the waters and see if things will be accepted when you talk like that, or if she is going to snip your pecker off in your sleep!
Nah man... problem is her parents are coughing up the $8,900 for the wedding. I'm NOT pitching in with ONE PENNY! Truthfully I'm a d!ck to her. She just asked me for financial help last week because she's broke. Well, I'm broke enough as it is so I said, sorry, no cash! All of a sudden I do have a bit of cash to fix the car?... Ah, I'll just make up some bullsh!t! 
You are just going to have to work harder to afford both oh and then there will be kids...Get ready for the fun.