A few weeks ago, I was driving my '85 corolla downtown through construction and I drove over a bump that was higher than it looked. there was a huge BAM!! that I heard under the car. When I got at my stop, I checked under the car and there seemed to be no visible problems (no leaks, etc). after I finished up there, I got in the car, STARTED the car with no problems, and drove somewhere else. when I finished up there, I got in the car, STARTED the car with no problems and drove somewhere else. when I finished up there, I got in the car and turned the key and NOTHING HAPPENED. There was no "click" from the starter and no engine turnover, but the lights and radio still worked. I took it to the shop and they replaced the starter. the car worked fine for a week, and then, when trying to drive out of the school parking lot the next week, there was a "click" but no turnover and no start. I took it back to the shop and they fixed the ignition switch because they said that it was old and that it was the culprit. it started fine after that for a week, but then one week later when I was getting ready to go to school, there was a "click", but no turnover and no start. I took it back to the shop and they said that they couldn't find the problem, but that they installed some sort of "bypass" wire, and that made it start. This morning, when I was getting ready to leave my apartment, the car wouldn't start again. there is a "click", but no turonver and no start. Some people have said that it is my modulator on the engine, and others have said that the gear switch is broken (in other words, whenever I try to start my car, the car thinks that it is in reverse or in neutral and thus, won't start). also, the car shakes a little bit when I am at a stoplight, which I believe means that my engine mounts are weakened. I believe that means that whatever is wrong is underneath the car. what is wrong with my car?