$$$.
Front engine, rear drive is easy to build. Good driving characteristics until you lose traction in the rear, which isnβt hard because thereβs not much weight back there. You get over steer which isnβt the easiest to deal with.
Front engine, front drive is cheap to build. Good driving characteristics until you start pushing the limits, then you get under steer which is easy to deal with by letting off the gas.
Rear engine, rear wheel drive. Same cost advantages of Front/front but has some quirky driving characteristics.
Rear engine, front drive: nope.
AWD: better driving characteristics, more cost and more weight.
Mid engine, rwd: similar to rear/rear, but costs more, better handling.