Strange boxer noise

Hi everyone - have an '83 bbi - had the belts, seals done about 2 mos. ago - since then a strange noise has developed. Whenever i go over even a minor bump, there's a sound almost like a snare-drum coming from the left rear - i can actually feel the vibration through the drivers seat.....i've checked the suspension, shocks, there is nothing loose in the engine compartment, i'm really at a loss - is there anything in-between the firewall and the cokpit where something could have gotten loose? it is quite loud, and is driving me nuts......anybody else experience this loud knocking sound from the left mid/rear?

I have been having trouble with my Door though. What is the deal we these things my Mechanic said that I should "shut up and not complain so much" but I swear I can not open them. My Aunt and I have been going in and out through the windows and I am just about fed up.

the above responses notwithstanding, my question is a serious one.

any serious input would be appreciated....thx in advance

check the struts. Depending on the year aluminum was used as a seal and it's been known to dislodge from the chassi.

Good Luck

we can meet if you want?

If a Shock is frozen or very sticky it will definately make a thump over bumps. How did you "check" the shocks?