another vote for uniroyal rainsport 3's. its the only tyre ill buy for both my mercs. the grip is amazing in the wet in both my big rear wheel drive C320 estate and little front wheel drive A210. its not just a wet weather tyre though, the grip in the dry is just as impressive. the price is reasonable, a 205x40x17 is about £70 fitted. not sure how much the 225x18 was though as i got them in my alloy wheel package.