Car is shaking bad

My E61 has bad front end vibration when stepping on the gas at 40 mph and faster, not when braking or coasting. I just had pads and rotors done. I checked that wheel bolts were good and torqued correctly. So, I'm thinking the front axle shafts? Or the driveshaft flex joint (but that's to the rear I think) Car is a 2010, close to 100k miles. Anyone go thru something similar?