Sorry for digging up an old topic, but I have experience with this problem which may help some people.
Check your front brakes for ceasing, which will add presure on the brake disc.
The front brakes use pistons to sqeeze the brake disc, there are 4 pistons per front caliber, it will only take one of these to fail. When you drive, you may notice no vibration for the first 15 minutes or so, but as the discs warm up and expand, they bind against the pad which has ceased causing one front wheel to essentially want to move more slowly than the other. This causes your vibration.
If this goes on for long enough, or you have old discs, they may have been warped.
Try and find a genuine refurbished caliper, have it cleaned and ensure it works.
This solved my problem, after months of wheel alignment, balacing, new discs, new pads.
If you have a vibration under braking, check the shims on the caliper are wide enough to prevent the pad moving in the caliper, as this too causes vibration, but more noteably under braking. The shims are tiny little things that are sandwiched between the caliper and the pads. (Sometimes shims can fall out during brake pad changes or you may have the wrong sized brake pad in).
Hope this helps some people.
