tsan you must be hard on cars mate .... RB5 is bomb proof!
I also defy anybody to break the kit front tower ... I know somebody who has done a rear but never a front!
As Carlin said, wishbones, front steering parts, rear uprights (unless you upgrade to 516-0s ... love to see you break those and a set of front shock shafts for other people driving into you (although probably not a problem until next years F3s
)
Kyosho cars are easily the strongest out there at the moment IMHO.