1991 Toyota Tercel Follow Up

What seems to be the symptoms or the problems then i will be able to give you my oppinion.

My brother says that the problem is with the exhaust. A bolt was missing. The previous symptoms I had described were a rattling noise when it starts and seems to disappear after I hit 35 mph. While the car speeds up, the sound gets louder. If you can suggest what kind of bolts are needed or qhere to get them it would be greatly appreciated. Thanks in advanced!:)

sounds like an exhaust problem, you will have to go under there and check all the hangars and heat shields to see if they are loose and let me know what you find.