I’ve been replacing all of the suspension on a 2006 R50, it’s fought me for a week now, broken rusty bolts. I paused for about 4 days and started back on it today. On the ground on the passenger front of the car, I found a rubber seal/o-ring that says “mini and 150” on it. All that I’ve taken apart has been hard parts, nothing with fluid in it except the rack, which I removed the boots to replace the tie rods. Is it from the rack? I’m assuming it fell out of something, but I haven’t a clue. Help.

This turned out to be from the control arm bushing I replaced.