I'm experiencing a minor problem: unusual engine vibration while parked. The vibration occurs sometimes. I was wondering if this is an indication that the spark plugs should be replaced?
The car has 20 000 KM (12000 Miles) and the spark plugs have never been replaced before.

Probably not, spark plugs are rarely replaced any longer. My mechanic once told me that he can't remember when he last changed a set.

They're supposed to last something like 100,000 miles.

Although, I suppose anything can fail. You have an XLR, right???? :yesnod :lol

Floyd

Sounds more like a plug wire to me. I've had cars where a wire gets cracked and it will run rough at idle, but when the RPMs go up, you don't notice it. Bring it into your dealer, they can test them quickly and determine if perhaps if a wire is cracked.