So... I have 170k in my r53 and it seems at about 65ish mph I start getting this wicked vibration under acceleration. Let off the gas and it goes away. vibration even shakes the shifter..... I was thinking lower motor mount or lower control arm bushings? what do you guys think?

 

Most likely your axles. Be careful with finding replacements. Don't buy cheap.

Check my post out:
https://www.northamericanmotoring.co...ue-speeds.html

 

hmmmm, I did hear a click when taking off from a light now that you mentioned it. replaced the passenger side this winter but I suppose the drivers could be shot

 

on car parts.com, found a few axles around here on 112k wrecks for around 90$? I assume axle means both halves with cv? I think the passenger side one I bought was off amazon. paid 100$ and something

 

Do you hear any clicking when you're turning? If/when you can get under the car to check things out, definitely look in the CV axles. I've seen this pop up a few times. I'd be very careful going with aftermarket axles. I've just seen a lot of issues caused by aftermarket rather than doing an OEM rebuild or OEM replacement. We have OEM replacements here for price comparison if needed. Come with a great warranty and you can get free shipping. Check out all other suspension components as well while you're checking things out just in case. Hope this resolves your issue.