I believe what you are experiencing is a misfire under a load situation,usually caused by a spark misfire. There is no Classic wheel bearing vibration causing such a problem,, they just get noisey. Under heavy accel, a worn inner CV joint can and will cause a vibration as you described,, But its usually noticable from a standing start. Balancer belt of time makes the engine feel vibratey all the time.. accel, cruise or shut me off. Your Shocks dont have nothing to do with it,, Honest. Before you go back to your dealer and show your lack of knowledge by the way of an attitude.. I would try and explain and DEMONSTRATE the problem to a QUALIFIED technician, and I would insist on a personal test drive,If you have been there before and paid for an attempted repair and it didnt correct the problem,any Diagnostic work/Time should be free of charge..You as a consumer have many rights,, The most important Is the right to be treated fairly !!!