shaken steering wheel
 

The point is my good friends ,every time that I'm going from 73 mph-about 80mph my steering wheel start shaken not that bad, but I don't like it any suggestion please, My car Boxster 2001 base.Thanks for any help as always.

check tire pressure. my box shook for a few weeks until i checked the tire pressure and realized the passenger side was about 6 psi > the driver side. after setting them to the same pressure it stopped.

granted mine shook from ~40 mph - 50 mph.

Could be many things, but the first thing that comes to mind when you say this, is wheel/tire balancing.

Perhaps look into getting all of your wheels/tires rebalanced, or even Roadforce balanced on a Hunter machine...

You may also want to check the torque on the lug nuts. Believe it or not it greatlyeffects vibtation. Ed

I have also read that the weights used to balance the wheels (they're affixed behind the spokes) can fall off...

Most likely culprit IMO is tire balance or tire wear.

check these in order - stop when problem goes away

1) Tire pressures to factory specs
2) Inspect front tires - any uneven wear?
3) Torque lug bolts to factory specs
4) Get 4 wheel tire balance
5) Inspect tie rod ends for looseness/wear
6) Inspect front suspension bushings for wear
7) Inspect McPherson strut top mounts for looseness
8) 4 wheel alignment
9) Replace tires
10) Replace wheels
11) Get another car