i keep finding problem after problem....HELP ME nissan tech read

[S13inyourface]

the whole right rear quarter is bondo...i found this out when a 1/4 inch of bondo was falling off....how much do you think this costs for a body shop to cut out the quarter and put a new one in? this makes me wonder if my car has been in the past, and if there is some serious damage anywhere else....and some other questions: my car wont pass emissions, im guessing its the cat, the guy also put an autozone muffler on the car, when the car starts? like a black mist shoots on the ground....what is this caused by? it shoots out of the tailpipe....it also needs a tune up i think and the tires need to be balanced/rotated/aligned all of that...the front tires are bald on the right side, im guessing it is because the tires need aligned or something.....i dont know where to freakin start....

[NISTECH]

You need to start with saftey[saftey first] Get the tires replaced and aligned.

Then start addressing the emisions failue and the black soot as they are probably related. Typically the soot represents a rich fuel condition. Do you happen to have the emissions test print out you can post the readings?

Worry about the body work once all the saftey and mechanical operating stuff are takin care of.