Car shaking when AC is on high.

It's very odd the whole car is shaking but check out that blower motor. If that's not it maybe it's misfiring under the load of the ac system. This will require a hands-on inspection at a shop though. Use this link to find a good shop near you. https://repairpal.com/repair-shops Alex

Agree - blower motor (assembly) is prime suspect - have even seen mouse nest inside fan blower wheel that will cause vibration - this will also be more pronounced the higher the fan speed.