I just purchased a 1989 Audi 90 Quattro..............i bought it as a project car becuase it has 167,000 miles and the body and interior is mint. It need a lot of suspension and brakes work though, which i had no problem finding parts for. I am having a few problems though

1)I need help finding a catback exhaust system that will fit...
2)The battery voltage light does not work but the gauge does...
3)The oil temp gauge light works, but the gauge itself doesnt...
4)The temperature gauge on the dash cluster doesnt work...

any help is appreciated but my main problem is with the exhaust............i need to find a good catback ezhaust for this car, i am looking for something good it doesnt need to add hp or make it sound loud i just need something reliable

-Thank you in advanced.........