The noise over bumps may be your front sway bar bushings - although w/ 20k miles I'd be dissappointed if that were the case, but you never know. Try searching this thread for "noise over bumbs" and you'll get allot of info on that issue.
As for the thumping - try and issolate where and the conditions the niose is comming from - front or back? Right side or left? At what speeds? Is it on all road surfaces? When the car is hot or cold or all the time.
Here a few guesses; A bolt or something lodged in a tire. A glob of grease on the inside of a tire rim. Maybe a rear CV joint boot failure...