Mustang 19 lb./hr fuel injectors supposedly fit in a 535i and work just fine. I haven't tried them, but others on this board can offer first hand experience. Recently, these injectors have been offered on eBay at a fraction of the price of the equivalent BMW parts, hence all the interest. A single BMW injector might cost $100, but a whole set of 6 essentially new Ford injectors might go for that much, or less, on eBay. I'm sorry I'm out of the loop guys. But, I don't know the whole story behind the mustang injectors and why they are so great and where to get them, what parts I need and all that stuff. The archives are hard to follow cause I don't know what to look for. Thx for any help Jay-z