my car

ofcourse..You'll be looking to either get a new car a swap in a brand new engine for it..

You can take it to a dealership and see if they'll flush the system for you

Chien isn't entirely true,, unless you run it, then you would be in trouble. Get it flushed and it should be fine

yes it will harm your engine.especially the 535 because it has a twin turbocharged engine it would choke it and probably cause engine failure if you were to run a whole tank. but most likely would even start. I would go buy a pump or have bmw have the diesel pumped out of your tank.

yes

yeah it will either blow everything or mess up your engine

yeh because deisel is more viscous (thicker) and will harm a petrol engine, epecially if it uses fuel ignition. however if its cleaned out properly and correctly lubricated with an engine oil (castrol) and fuel injection an carb. cleaner (put into the fuel tank) the damage can easily be repaired with not that much cost. proper draining knowledge will be necessairy if u r 2 do it urself. oh an it also depends how long uve had it it there and how much did u put and was there any petrol it in before and if so what is the concentration. All these senarios can have different solutions but usually draining n fuel injection cleaning fixes most problems including fuel economy.