The policy I bought for my wifes car 2 years ago (M/B CLK 320 '04 at the time it had 11,000 mi, now 21,00) was through the AAA and was Mercury insurance.
Coverage is till 2014 or 80,000 miles I think it was about $2800.
Work could be done at M/B or independent shop, shop calls them ok's work and gets paid directly.

__________________
BMWCCA # 12660
14 GLK 350 M/B (hatefull POS gone)
05 CLK 500 AMG Cabrio
07 530xiT
09 Boxster