RWD can't get up a wet paved road from a standstill?

[mbt]

went to megamall last night when it was raining hard, and there was a bit of drama on the carpark ramps... a Starex couldn't get up the wet ramp and was just vaporizing its rear tires to thick, expensive smoke. the security guards had to push it up the ramp.

the Adventure behind it (which had to stop to give the starex room to roll back in case) and in front of me had a similarly hard time launching, the rear tires simply couldn't find any grip and the driver was flooring the pedal to no avail. it had to be pushed up as well.

however, the Venture I was driving didn't have any problems going up the wet ramp from a standstill, and the Civic behind me didn't have a problem too

bakit ganun? disadvantaged ba talaga yung RWD up wet inclines?

what could you do to manage the wet incline if you were driving a RWD vehicle, in case you had to stop and couldn't get up? would applying the brakes (foot brake or park brake) while gently opening the throttle do the trick?