Q: vibration/buzzing felt in steering wheel, seat, gas pedal, shifter 50 mph up shifted to neutral with engine off

From new, tires were balanced 3 times, also switched to winter wheels - no improvement.(I have 40 years experience as a car hobbiest) I did this test procedure: 1)supported chassis 2)removed wheels 3)supported ball joints to simulate loaded suspension 4)disabled all drivers assistance features 5)idling in gear a wobble is seen in both cv axles - (inner cv is a splined fit into transaxle with some looseness) 6)accelerated to 60 mph the same vibration/buzz is felt starting at 45 mph 7)no unusual noises, no looseness in wheel bearings, no vibration felt on struts. I feel it is a defective cv joint or out of balance axle. Noticeable on smooth roads, test driven other cars including my 21 year old VW GTI so it's not in my imagination(some are smooth, some vibrate). Dealer is willing to call in their service expert to test drive but they themselves are not sure there is a problem

My car has 7000 miles.
My car has an automatic transmission.