I've found the connectors at the receiver to be a weak spot, with a sealed transmitter board (similar to plastidip). I used a factory waterproofed ESC from MRT back then. Current receivers and escs might feature buttons that may make things a bit harder to coard properly.
Tamiya TRF101, Corally F1 SL, 3Racing F1-09, Kyosho Mini-Z MR03, Corally SP12M, Tamiya SuperShot, Kyosho Optima Pro, Duratrax Vendetta.
Home track: http://www.amcaracing.nl