My old car had this circular thing that looks like a blob of spiderweb. You guys know what it could be? it was the size of a dime.

 

Did your car get egged? if so it could be where the egg hit the car and broke apart. I had tons when my car got egged, and the only way to fix them is to have the car painted.

 

It sounds like "spiderwebbing". There is a good chance that an agressive polishing might lessen or remove the look of it. You can either do this with a machine polish without fillers and then wax over. Or you can get something like Meguilars scratch-X, which has like fillers in it. It will maybe hide. It depends really how bad it is.