Strange noise
 

I just notice vibrating and a subtle knocking noise coming from the center right under the arm rest. It seems to happen when I accelerate fast and hard. I thought it was the front right tire, but it's fine. Any thoughts?

cardan shaft bushing. part is 400 from vertex or 700 from porsche. maybe a 2 hr job. go to rennlist. plenty of pics and info there.

Thanks!

Okay, ended up being the drive shaft.. Luckily extended warranty covered the repair. The dealership still ended up squeezing $435.00 for the main battery. They said mine was completely dead and i was driving on the auxiliary. They quoted me $1,500 for the 40K service, tune up, oil change etc... How hard is replacing the spark plugs? If I try to do it, will I get any error codes or warnings? Thanks!

The plugs are very easy. You remove the plastic deco covers on each side, the air pump on the drivers side and the engine stabilizer on the passenger side. Next you remove the coil over plug and then the plug. Very simple and you can inspect the coils for cracks while you have them out.