RD Sport might still be around... Read my posts 416 and 419 here:

https://5series.net/forums/e61-touri...1/#post1587969

 

Resurrecting the most recent E61-specific sway bar thread I can find.

Has anyone upgraded their e61 rear sway bar recently (like since 2023)? I'm in the US and cannot find a supplier for the M5 part (33552283036). It does not seem RD Sport exists anymore and I've read elsewhere the E60 rear sway definitely does not fit the E61. Thoughts? Thanks!

 

Theres a few options as the E60/E61 rear bars are the same; also rwd and awd are interchangable.

The M6 vert/E61 M5 have a 20mm swaybar (used or new are options) whereas the M5/M6 have 18mm swaybars.

I installed a 545/550 M-sport rear swaybar (33557906822) which is 16mm, some of the pre-lci ones didnt have the dynamic swaybars so they had larger ones. That is vs the 12mm stock rear in awd E61's ( E60s there was also 13mm and 13.5mm for non-sport, 14mm for sport rwd)