I am finding the noise level from the Fabspeed exhaust to be louder on the driver side exhaust than on the passenger side. Am I paranoid, or am I on something?

Second, do any of your cars shake a little when being switched off? I find the shake to be coming from the engine area, mainly, I believe it is mostly coming from the driver side as well.

On my previous 997 C4S, the car does not shake at all when being switched off.

 

I can't answer your question about the Fabspeed exhaust sounds but suggest you check out the following thread about shake-clatter upon engine shut-down: https://www.6speedonline.com/forums/...33#post1134333

 

Sounds like something is loose on the driver side, check the clamps.

 

Thank you for the link, but my car is an automatic, so there is no clutch need to be depressed.

 

You have a clamp issue, I found the supplied v band clamps btwn the cat and the rest of the system to loosen and fatigue. Try and retighten them first. I solved the issue by substituting some oem porsche 996 clamps that have a much larger bolt and solve the issue. pn 996 111 108 00. mount them in the vertical position, cost; ~30$, time ;10 minute job.
I'm including clamps in my deal.

 

I Made A Silicone Seal Between The Clamps And The Muffler , Let Me Know And I Will Mail You Some....

Gee-bee
Gee-bee Aeroproducts

 

Thats because your ears are closer to the drivers side.

 

check for the clamps coming loose, also when the car is cold you can spray some soapy water on the joints and see if they bubble, this would indicate a leak.