I had these sturdy 6 and 3 ton U top stands already, so I'm making do. If I was starting from nothing, I'd get some nice flat top stands that work better on these cars. There is no available pre-made substitute that works the same. These crappy wooden ones I made have no flex and spread an even force on the jack pad socket. These spots are notorious for rust and this is one of the causes. This puts uneven loads at the jack points that can stress and bend the BMW plastic pad and then the metal behind it. On thing for certain, all the plastic ones do not have enough stiffness, and will bend and distort on U topped stands.

My kids helped measure, glue, sand, etc, so that was some quality time spent making something with them in the garage. Sometimes it's about satisfaction of making something vs buying something made.Thanks! Sometimes I can't help myself as I love to make stuff to the point of fault. So far I set the whole side of the car on just one, and it looks plenty strong. I picked the heaviest piece of Oak I could find with the most flat and tight grain. The two pieces are set cross grained to each other to prevent splits. I rounded the tops of the center pieces with a rasp and sandpaper so they fit the contour of the jack pad inside pocket. I glued and double sided screwed the center pieces to the bottoms. The oak is very strong and does not bend. This allows you to set the jack stands without fumbling with them. This way they stay put when you pop them in place. I cut the center pieces so they fit snug in to the jack pads. I just made these out of 1x4x24 (.75' x 3.5') Oak from the lumber store, about $5 and an hours time to make four of them. The plastic ones bend, and the metal ones look sketchy like they may slide off the jack stand. I like the hockey puck metal or plastic ones for when using a jack, but they do not work that well on U shaped jack stands. I was tired of not having good adapters to support my car on jack stands.

Flat top jack stand adapter