I can recomend a fantastic shop. Browning's in Manasass. I was rear ended in Tyson's a couple of months ago in my SL600 and they replaced my entire rear end and matched the paint and no one can tell the difference. Bobby Browning owns the shop and won't cut corners on his work. I'll post before and after pics tomorrow when the weather is better. He's also doing a repaint/restoration on my 560SEC and I'm confident it will look great! His number is (703)369-3020. Tell Bobby that the guy with the green SL600 had you call.

Edit:
Browning's Auto Body Inc
8421 Maplewood Dr
Manassas, VA 20111
(703) 369-3020