From Paul, blogging at Hawsepiper, talking about driving a very upmarket rental car:
Driving a Jaguar on the highway is like wiping your ass with silk. OMG.
Er . . . I don't think Jaguar is likely to use that phrase in their advertising, but I have to admit, it's very descriptive!
(I would, however, like to know how he came up with the comparison. Was it based on personal experience?)