A Planted Technology seat bracket for the BMW 3 Series on the E21 chassis, 1975 to 1983. Part number SB128.
The first 3 Series, and the car that established the format everything since has followed. The E30 that replaced it takes SB034.
Getting genuinely rare
E21s rusted enthusiastically and very few survive in good condition, particularly here. The 323i is the one with the following, being the first six cylinder small BMW.
That scarcity is the argument for keeping everything. The bracket picks up the factory mounting points, so the original seats come out whole and go back in. E21 interior parts are effectively unobtainable new, so store what comes out somewhere dry and label it.
The floor check is not a formality
These rust in the floors, the sills and round the strut towers. Get the carpet up and look properly. If the metal is soft, sort it before a seat goes near it, because a bracket can only feed seat load into sound structure.
A period trimmed shell suits an E21 far better than a modern bucket. Handed, so order twice for a pair.
Have you written anything about this exact product?
Yes, we have covered this exact product: Top 5 reclining seat choices for your BMW 3 Series Sedan [E36], including our fitting guide, and Top 5 reclining seat choices for your BMW 3 Series Coupe [E46], including our fitting guide. That is first-hand coverage from our own builds and showroom, not brochure copy.
Will this fit my car?
This frame is made for the BMW 3 Series. Chassis code and years matter more than the badge, as floor pans change between generations, so if your car sits near a changeover year, send us the registration and we will confirm before you order.
Which seats does it take?
Check the bolt pattern in the specification against your seat. The Compatible seats tab above lists what bolts straight on. If your seat is not listed, tell us what you run and we will confirm the fit.
Do I keep fore-and-aft adjustment?
Only with a sliding runner between the frame and the seat, which is a separate part on Planted frames. If more than one person drives the car, budget for the runner. Our guide to sliding runners explains the options and widths.
Is this for the driver or passenger side?
Both sides are available on this listing, pick driver or passenger side at the point of order (sides listed are for right-hand-drive cars). Left-hand-drive car? Ask us, as the sides swap over and availability varies by model.