2003 Cadillac CTS wobbling noise and vibration

Have had the car looked at by Cadillac and Midas.
When I run over a sewer cap with left front tire I get just the thump, thump as you hit both sides. When I do this with the right front tire I get the thum, thump and a wobbling sound and vibration.

No one seems to be able to determine what may be wobbling. Driving me crazy.