BMW Repair: 1999 BMW 528i vibrations, personal mechanic, control arm bushing

Question
This may be multiple problems but I'm posting the whole history.

I bought my 1999 BMW 528i in Jan 2005 from a dealer who gets cars from auctions.  Had it inspected by a local reputable BMW shop and they said it was ok.

In Oct 2005, at the recommendation of my personal mechanic (not the local shop), I replaced the struts.  He put in Koni sports struts which are supposed to be good.

Since then, however, I feel the car has been riding a lot more bumpy than before.  It used to drive like it was almost sliding on water and now, it feels like I can feel every bump in the road.  I asked my mechanic about it and he says its because these are sports struts.  He wasn't sure but he said replacing the springs on all 4 tires might help matters but I avoided it as I wasn't convinced.

I recenly got the front wheel rotors and brake pads replaced and rear wheel brake pads replaced.  The mechanic had to redo the front rotors as the first set used to make the car shake when I used the brakes.  The problem went away after that replacement.

Now, the problem is that at high speeds (around 65-70 mph), the car shakes.  I can see the steering wheel shaking as I'm going on the freeway.  Braking just exacerbates it.

I showed this to my mechanic and he thinks it might be the front control arm bushing which needs replacement.

I trust my mechanic as a person but am not sure if he's diagnosing the problem correctly.  I need to get another opinion.  Any ideas?

So, two problems, to summarize..

1. After replacing struts  with new Koni sports, the ride feels more bumpy.

2. The car shakes at high speeds on the road. (Diagnosis: front arm bearing..)

Would appreciate any help.  I don't know much about cars! Thanks.

--Michael--

Answer
Mike the struts are self explanitory. Replace the struts with factory ones if you do not care for the Koni's ride feel. As for the vibration front control arm bushing are a common wear item on BMW's and usually last 50-70k miles. They can cause the condition you are experiencing aswell as cause dymnamic alignment issues causing increase or irregular tire wear. I would recommend replacing them if they have leaked out their oil or the rubber is cracking. Please make sure you have good tires of a reputable brand. No Kumhos, Sumitomos or other off brands. I don't even like the Dunlops and the Contenentials at the dealer. Use a Michelin or the like. Make sure you don't have any bent rims by spin checking them off the ground. Have the tires dynamically balanced or replaced if worn. If you have aftermarket wheels and tires try swapping your original set back on and test drive. Also make sure your brakes are good and that the rotors aren't under the thickness spec. That will cause vibration when braking. If you replace tires, struts, or control arm bushing it wouldn't hurt to get the alignment checked and adjusted if needed. There are some things to look into to solve your troubles.
-Evan