[BMW603]

OK-- this is the second year this has happened, I park this 2010 328i x drive in the winter (have a capable x5 for winter) park it inside clean garage from mid Oct to April - full tank of fuel, stabil & bmw charger. the first run I verify tire pressure and head out.. (about 2 miles from my house is the highway) I get up on the highway.. cruising speeds (so far everything is good) say 5 miles out on the first day I unhook from life support..hit the gas a bit (not mash to floor) immediately it begins to vibrate service engine soon light illuminates. next exit end of ramp I stop it almost feels like its going to stall and from a stop take off vibrates harder and has no power.. but you can move along.. park in space. turn off turn back on.. light is off and all is good, normal driving for the rest of the season. (last year mid drive , mid shutter it just fixed itself no restart light went out and all was normal) dealership said it has no codes - car has 12,000 miles. any ideas.. ? like I said it's OK now but I was curious.