RCU Forums - problem with electronics on rush evo

hi yesterday i took my hpi rush evo to a local bike jump place. it had been raining previously and so there was quite a lot of puddles everywhere. i accidentally drove into a couple of them and stalled it but i managed to get it going again. Anyway i let a friend have a go and he somehow managed to drive it into a huge puddle which was about 20cm deep. it was in there for about half a minute while i tried to get it out. i have got all the water off the car but now if the radio goes about 5m away from the receiver the car seems to not pick up the signal and just sit there. i do not know what the problem is and have changed batteries e.t.c i have also put the receiver out to dry more.
oh i also sprayed it with WD-40 could that have ruined it somehow?
here are some pics