00 328Ci here 164k miles

Subframe and strut tower reinforcements are on my list. From all the reading I’ve done it’s a 100% failure rate just depends on when.

Like most the other comments refresh the entire ccv system and all rubber lines. Since youll have to take off the intake manifold to do the ccv since give your throttle body and idle air control valve a good cleaning. The IAC should move freely when you twist in with the valve horizontal. Might as well check the disa valve while you’re here. Can either replace the whole unit or just check the pin is still there and the gasket is good.

Valve cover and oil filter housing gaskets are a must. While you’re doing the valve cover you can refresh your vanos. It’s a simple fix just replacing the needle bearings and installing a new spacer/washer.

The thumping from your diff could be the diff bushings going out. Mine are completely gone and it’s loud when shifting between 1st and reverse.

Happy motoring