Tires OEM BMW or Triangle

HD thrust arms are an improvement without too much sacrifice. Better shocks as well. I’ve found tires make a huge difference with the E39.

Narrow, low-profile tires aren't as forgiving over potholes, especially when riding on the 20" wheels.

+1 used those on my e90 BMW last year during the 'record' snowfall and the were great.

I run chinese tires on my Peugeot, they are just called TRIANGLE

I drove a set of Triangle Talon tires for a year on my SVT. Dry traction was surprisingly not terrible but they were AWFUL in the slightest hint of wet weather. Forget cold weather.