This is a wrench designed for the use with the BBS RC wheels on my MK4 Volkswagen GLI. It should also work with the 2002 337 GTI as they have the same wheels.
I recommend printing at a 0.25mm layer height with a slightly high extruder temperature setting for good layer adhesions. Print with at least 0.8mm wall thickness an a 25% infill. I printed with extra wide infill line thickness for extra strength and 1mm top/bottom thickness. It's very solid and worked great at taking off the center caps of a project car which I had picked up with a blown motor which had been sitting for over four years without the wheels coming off. It was designed with an extra long and raised handle to give clearance against the spokes for turning and because of this, you will need to print it with supports.
If there is demand for it, I will make more versions with 337, VW or any other logo (or no logo) on the handle.