Booster seat for the driver???

Use anything to start with in order to find the needed additonal height. If the distance is less than about two inches at the rear of the seat bottom, You can add blocks and longer bolts to the rear seat mounts. The bolts should be high strength bolts, not the usual cheapies.

My wife is 4" 11" so we always have to modify the car seat in someway for her to drive. In our 1992 Miata she uses a 4 inch thick foam rubber seat cushion covered in a grippy cloth material to prevent slippage on the cloth seats. On our cars with leather or vinyl seats, the grippy cloth is even more important. We have also used the longer bolts with spacers on the seat to raise the height on some of our other cars, but then that makes it uncomfortible for me to drive the car, so that automobile is dedicated for her use only. Another problem is getting her close enough to reach the pedals. That of course, gets her too close to the driver's side air bag (our Ford Taurus had adjustible pedals that worked great). In our other cars the driver's side air bag has been disabled because we ALWAYS wear our seat belts. Newer cars have depowered air bags, so this may not be necessary.

Desordre

My wife is 4' 11" also, and has been driving our '96 for ten years without any problem at all.

His wife may have shorter legs and a longer torso than your wife, or even just a different body build, though I am not about to go into that any more than I already have. ;-)

I am only 5'9", but I still have to put the seat all the way back to be comfortable because I have long legs and a short torso.

Having less length in the body also puts my head well below the top and below my rollbar, always a good thing if you are tumbling down the highway.....

Pat