Allow me to add...
The 560 will not dissappoint you. It has the power for any driving situation, including towing. You'll pay about $140-$180 more per year for gasoline, but it's a small price to pay for the extra power. The 560 is the finest sedan ever built, IMHO. Even though I have a 500E, I keep going back to the 560 because it is such a pleasure to drive.
2002 ML320 (thereby making my 560SEL my "spare).
1992 500E, pearl black, 27,000 original miles as of 7/2003.
1990 560 SEL, black pearl metallic, sweetness to drive. Fully outfitted with driving countermeasures (Beltronics radar/laser detector and Uniden BCT-12 Bear Tracker scanner).
1985 Porsche 911 meteor metalic gray, a rocket to drive.
1988 Chevy Silverado pick-up (gotta have something to drive to the rodeo!)
1978 Corvette Indy pace car for show
1971 Opel GT for sentimental reasons