squeaking coming from under the car and a thumping

[bodhie30318]

squaking and thumping noise coming from under the car happens when i hit bumps mostly

[Speedtouch]

Welcome to the Zone! Sounds like your bushes may be worn, particularly the front wishbone 'lollipop' ones, possibly also rear subframe bushes.

http://www.e30zone.net/e30zonewiki/index.php/Suspension

[Brianmoooore]

Short answer is whatever is worn. For a more detailed (and useful) answer, you'll have to narrow down the area the noise is coming from a bit.