When i'm on the highway my S2000's shifter vibrates pretty badly, i was wondering if this was normal for our cars of if its just mine that is screwed up, also if you hold the shifter it will stop it from vibrating.

 

Shifter vibration is par for the course. Don't drive holding the shifter unless changing gears.

 

yup. vibrating is normal. and as stated, don't hold onto it or rest your hand on it. that can actually cause some abnormal wear.

 

I've found that a Ti voodoo knob will eliminate it

You could also try an 02-05 knob. It's steel, and heavier. Prolly reduce it...

 

why is it bad to hold onto the shifter while driving? how would it wear on stuff when it is in gear

 

If you are putting pressure on the lever while in a gear it can wear on the synchros.

 

And the shift forks that move the synchros.

Besides, it's generally considered to be good practice to keep both hands on the steering wheel when not shifting gears. If you do keep your hand on the shift lever, I think most of us do at one point or another, just make sure you're not putting any pressure on it.

Drive Safe,
Steve R.