Originally Posted by Jim H

First, are the tires over-inflated? The sticker under the fuel door will tell you the corrrect pressure.

Then, has it gotten really cold? Cold weather can stiffen up the shocks, making the ride seem tighter. Water on/in the shocks can freeze, and make the ride quite stiff. Worn-out shocks usually make the ride seem more floaty and sloppy, not rougher.

No. The Mass Air Flow sensor and transmission valve body are unrelated.

In fact, Mercedes-Benz has a chain. They are called dealerships, and they are national...