vibration/shutter noise

[hutche]

hi all,my 2007 ve lumina has recently picked up a problem,at different speeds 70kmh,100kmh & 120kmh it seems to shutter at what id say is auto transmission,if i back off or accelerate more it stops,starting to think its either engine mounts or transmission mounts?im pretty clueless when it comes to mechanics so any help would be appreciated,cheers

 

[MYVESSV8]

when was auto serviced last, possible mounts but a service is cheaper and you'll know it wont need doing again for a while,
tyres may need rotating, wheel alignment, wheel balance, look at the easier things first, if you know someone with a scanner check for pending codes too