Ok, so I'm no car genius, but something is definitely wrong. I own a 1999 Pontiac Grand Am and something is always going wrong with it. This particular time, I was leaving a doctors visit and when I put it into drive, the car began to vibrate (well, more like shake violently) when I slowly applied pressure to the gas pedal. The vibration seemed to fade away as my speed increased, but when stopping at the next light, I found that the problem started again. I pulled into a parking lot and shut it off, sat for a moment, then restarted. The car was fine in park, but the moment I shifted into gear it started back up again. I checked the oil (seeing how it had been a while) but found that I was still just beneath the full line. I continued on my way home and found that the problem subsided altogether about three miles from my house. What in the world is going on?
(side note: The car has also had a little trouble starting lately... It does start every time, but sometimes requires a longer turn of the ignition.)