Alex, its not the spark plug fowler..

back to the old drawing board...

 

What does it sound like?

 

Not to sure... sounds like a rattling noise, coming from around mid to rear of the car. Only during deceleration though at approximately 6k rpms.
You cant really hear it in 2nd gear as the exhaust is so loud.. but its clear in 3rd.
Dave heard it this weekend, when i let him drive my car to dinner on Sunday night.

 

Could be a bad syncro or your Spoon exhaust's resonator on the fritz. Either one of those you wouldn't be able to figure out without professional help

 

Neither one of those sound fun either..
where's the acker man when you need him ....

 

Your heatshield is loose.

 

That could be it too....

 

Hmmm... damn i dont want to go crawl under my car again

 

Good luck.....or just do it another day.

 

I think it is time to watch a movie and call it a night