It's basically like a banging, metal on metal knocking if you will. I've been told its a failed rear shock mount which is plausible, but I just can't believe that the car would chew one up so quickly. It just turned 15k yesterday and those RSMs have only been on for 8k miles or so since the stage 1 suspension was installed.
1997 Aston Martin DB7 - Merlot Red
1999 Dinan S3-M3 Convertible - Titanium Silver
2008 Mini Cooper S Convertible Sidewalk
2011 F25 X3 xDrive35i - loaded w/19's
2011 BMW 328i - Space Gray on Saddle Brown