This letter came from a reader in Salt Lake City, Utah who was suffering from a case of the shakes:

Hi Matthew,
How is your week going? I have a '04 Maxima. At the moment and when I brake, the car starts shaking, the steering wheel most of all. The harder I brake the more it shakes. I've noticed that with my other cars as well (I used to own a '96 Plymouth Breeze/'89 Olds Delta 88). Am I doing something to cause that? I have a heavy foot but I still drive gently (unless I'm in a rush of course :S)
I drive between 60-100 miles a day (a lot!!!) and the car is currently at 110,000 (got in last august at 74 ,200) Someone told me it might be my brakes. But they don't make any other symptoms for me to suspect that, (no noise, not even when it rains or snows, brakes just fine). I'm not really mechanically inclined but I am not a novice either ... can change my own tires and oil... check my fluids regularly.
What do you think could be the problem? Really appreciate your help.

My week's going great, thanks! Going to do some top-down motoring this weekend in the '60 Porsche so things can go nowhere but up.
You most certainly have a brake problem -- warped front brake discs. As you use your brakes, heat builds up in all of the brake parts. Get it hot enough, and the brake disc (or rotor) will warp slightly. Unfortunately this slight warp is enough to make your car feel like a Cuisinart when you press the brake pedal. There are usually no other symptoms present, no noises other than the hideous vibration you also feel in the steering wheel.

Luckily, replacing your brake discs is a fairly straightforward DIY job (especially when you use our detailed step-by-step!). Replace both of the brake discs and you'll be stopping smooth once again. While you have everything taken apart, it's a good time to replace your brake pads, too.

That should fix you up. While brake discs warp over time for no reason other than wear, in your case you might have a driving habit issue, considering it seems to happen to every car you strap yourself into. Are you driving an automatic transmission car with two feet? Or do you "rest" your foot atop the brake pedal until you need the brakes again? Any unnecessary depressing of the pedal while the car is moving, done on a repeated basis, could warp the discs.