Another problem I have seen.
In real life:
If you get into a rear-wheel-drive car and hold the break and give the car gas (clutch work is involved) the front tires will grip as long as you want, while the back tires will slip. This is a very common practice for drag racers who want to warm up their rear tires before a race. And even with drag car with large rear tires and smaller front tires, because the rear were quickly put into traction loss, the smaller fronts can keep traction and not slide -- this of course is only to a point, eventually the rear tires (if large enough or with soft enough compound) will over power the front tires' grip.
In LFS:
I use pedals with the break and gas pedals being on separate axis. I have tried to do burnouts on RWD (I'm pretty sure I used one of the GTR RWD cars -- I can't remember, and I am not home to check) cars by holding the break, holding the clutch (not necessary), giving gas, then releasing the clutch. The result is the rear tires squealing and the front tires (if the break is pressed enough) sliding while locked up. So I messed around with it a bit trying to give my front tires better traction -- slowly letting on the break, get them right to traction loss without going over; but to no avail. I went into the setup and even put R4s on the rear, and R2s on the front. But still the front tires just slide.
I find this all very odd, because the rear tires with complete traction loss (only slipping friction) have more traction than the front tires with no traction loss -- and these cars, in general, should be front heavy, so the front tires should have more traction than the rear innately.