I've used US Millworks steel plate mounts that utilize the front tow hook mounting holes; formerly on the 230i xDrive and now on our '15 MINI Roadster S and '23 x3 M40i. They are very robust.
Yes...it is an offset mount and certainly not symmetrical but they are a solid mount that avoids the drilled bumper cover issue if that's a consideration for you. The multiple mounting configurations allow you to avoid covering any front camera sensors.
www.usmillworks.com.
Well..I checked with U.S. Millworks...unfortunately, they do not have a custom mount post for the G29 and indicated they don't plan on making one available. Guess with end of production already announced for Mar 2026; and limited number of z4's, that's not too unexpected. I'll need to source something else should I pull the trigger on a G29...that Mar 2026 date makes it a serious consideration for me!