Hi guys ! My car has 70,000 miles on it and just started to have a vibration at 60 to 70 MPH. It seems to be worse when I let off the gas. Here'* what I have had done. Two different sets of tires , wheel balance x5, new brakes front and back , rear shocks, said front balanced good. Front strut assembly install and alignment, front CV axle replacement. And then , front cross arm assembly and alignment. I even had a transmission flush. I have spent 1000.00 '* of dollars and still have the vibration. I love my Buick, it'* in excellent condition and would like to own it for another 10 years. I just don't know what else to do. I'm a 60 year young woman and am tired of forking out money for things that I don't think need to be done. Any suggestions would be greatly appreciated !

Did the check the motor mounts. These are usually not dependent on vehicle speed but hey.
Where is the vibration? Steering, floor etc.

I'm feeling it in the steering wheel and it'* kind of minor. Everyone says not to worry about it but my car has always been a super smooth ride. I'll have my friend whom I trust check the motor mounts for me. Thanks

Were the front wheel hubs ever replaced?

The torque axis mount Id think would be most sensitive to speed and the rear one possibly, but id say subframe mounts before id condemn the rear one on trans without seeing any of it lol

The front trans mount, drivers wheel well, passenger well(Or engine compartment by belt) and a quick on the ground looking under at the subframe mounts is wise,
id wonder if CV axles are good and if the axle nuts are torqued down all the way
then id wonder if wheels are all torqued properly on to the hubs, struts are good if you push down each front 3+ times if you get good rebound AND the car maintains the proper level (equal if not just to how it was before you did the push down, use a tape measure if you dont trust eyes)

then another unorthodox test but one that doesnt require any mechanical skills or time involvement like the other checks may
Find a road or parking lot somewhere and drive in reverse straight line and do a few hard stops
Like ABS activation stops lol, and optionally at a lesser speed reverse and turn all the way to lock then to other lock. if you cant find a place for the hard stops this prob would work in place of it.

Then drive the speed. report findings.

I didnt notice the strut and cv axle thing.

WHen did you get the strut and the cv axle? Do you know what brand? Your car has, what i presume, an OEM Strut on one side and a not-OEM quick strut of any kind on the other? Or did they use the original spring on a new absorber? If you dont know its okay, but that alone can be the issue(OEM strut vs aftermarket side-by-side youd see what i mean)
Also, you said front balanced well. did you not have a 4 wheel balance? Were these balances done on the car or off the car? At rotation? How old are the tires/balance job? What brand tires?

With your mileage i am more inclined to think this is a wheel/hub/steering/tire problem, but ill wait to hear more. Lots of variables as you can see by my questions. Also your statement about things you dont think should be done, are you using the same service center for this, and if you want to expand your reasons for why you feel that way, Id hear you out.

Shops and mechanics shooting from the hip either to scam you or just pure laziness/confidence in flawed reasoning is very real, so dont think youre insane for the thought. your cars mileage itself tells me there probably was good components needlessly replaced. the only exception would be shocks or bushings on control arm possibly failed due to fluid/sealing failure which is age not wear. The CV axle is also suspicious. The brakes even are suspicious unless they were rusty/sticking/wore wrong

Get the tires balanced on a road force balancer. Have then use it to check for bent rims and hard/soft spots on the tire.

These are especially sensitive to bent rims, balance issues, and tires with hard and soft spots. What you are describing is something I went through on my 1997 LeSabre.

No they were not. I have a mechanic coming over tomorrow to look things over. Thank you . I'll let you know what he says.

Thank you for the advice. I'm having a mechanic friend stop by tomorrow and I will give him this information.

Regardless of his findings, if you do seek a road-force balance that cathedral mentioned, it can and should be very helpful even if not the cause of your problem, road force balancing balances wheels and tires basically as if the car literally was going down the road and somehow a balancer could balance under that circumstance(which they do a great job of )

I believe they balance it for a choosen speed, so if you noticed an exact speed its worse or you prefer to travel, say, 72 or 67 (random examples) mph, you could balance for that and then a hopefully smooth ride can become smoother yet

I would definitely let your friend look at things first before that, incase you have any problems that need to be addressed first