recently purchased a 2012 z3 with the zr409 that was sitting for a while but i wasn’t aware of it filled it up with gas took it out and ran like garbage come to find out the 30odd gallons of fresh gas i put in mixed with the rest and it would run but not great and then would die under load drained the tank completely and replaced the fuel filter added an additive and changed all 8 plugs ( a few were fouled) now runs great fast forward to this past sunday i go to put it in the water and it has no forward or reverse. checked transmission fluid level and condition it’s literally perfect shift cable is fine operates just fine on and off even manually moving the shift lever on the transmission still nothing v drive fluid was mixed with water and over filled obviously just changed that as well i’m not too sure where to go with it at this point im trying everything i can before i take it to a service center any help is appreciated.