On car injector cleaning thru the fuel rail
I am going to try the OTC canister which is powered by shop air and should do a fair job. I don't think the system comes with the adaptor to hook up to the beemer fuel rail but I should be able to mate it to the hose from my fuel pressure gauge.
Speaking of the seafoam treatment, I have always just used B12 carb cleaner sprayed into the intake manifold until the engine stalls. After short heat soak and restart it seems to do an OK job.