point to note on your power stage i run a 16v and changed my power stage unit for one which i got from a another 740 which i owned the parts looked identical and had the same bosch number after driving the car for a day or two it suddenly cut out while driving at about 30 mph , " ? " i waited a few minutes and it fired up again only to do the same thing about five times on the way home so i put the original part back in no problems since,my point is that this unit generates a lot of heat on seperating the faulty ps unit from the heat sink i noticed that there was little to no heat dissapation compound,could have been causing it to overheat me thinks,another tip is to run two batterys one sits on top of the other unconnected and just swap them over every couple of weeks that way youve got a good spare if you experience cut out faults.