For a 500E, probably not unless you really wanted a more track biased car. I know on 400E/E420's the fittment of sticker (plus 1) rubber can make you wish for more roll resistance but on the 500E it is ready to go once you bolt the 17"ers on. Even if you fitted 10" wide rears on 18" rims you could still probably get away with it. That self-leveling rear suspension helps, the Porsche tuned suspension package just seems to do well with plus fittments. (not like MB has ever been known to "under-tire" any of their cars...j/k) My bottom line advice would be to put the plus fittment on there and see how you like it. If you believe you need more roll resistance then take it from there. So far, even many of the rabids seem content with just the wheel/tire upgrade.

Hope this helps...Lee