My r171's (2005 SLK 350) battery died after 11 years. Since 11 years is a very long time, I am inclined to buy a genuine OEM battery. This website has the best price (here on mercedespartssuperstore.com http://mercedespartssuperstore.com/parts/2005/Mercedes-Benz/SLK350/index.cfm?action=partDetail§ion=ELECTRICAL&group=ELECTRICAL&subgroup=BATTERY&component=Battery&partnumber=000982300826&vehicleid=185747&siteid=217866). Did any of you buy from this website recently? Are there other options?