hi all i drive a zafira gsi i have had 19ns on and had vibrating through the steering at 60 mph

i took the wheels to be balanced and the bloke said they were fine and did not need weights .
so i put it down to the wheels being tsw legend multi fit with the moveable hole and they wernt fitted properly and maybe being a bit to big for the zafira

i have since bought a nice set of vxr 18 and still having probs and the wheels a straight as a die

it was sugested i have a look at drive shaft weight !!!!!!!!!
never herd of this can any one enlighten me
could this be the prob
does any one no if i can see it from under the car
and how it will cost me
i have had new brakes and discs as well