smoke out of the back
 

When I got back from a trip ( I was gone a few days) and started my car I got a lot of gray smoke coming out of the car. I drive a98 Passat GLS. After a few seconds it stopped. This makes me believe I may have an oil leak near the engine or something of that nature. Does anyone have any ideas?

On a side note, my CD player skips a lot (the tires in the back are a little worn). Does anyone have any cheap ways to keep the CD player in place (the old owner apparently took the tool kit and med. kit out of the back.