With a bike engine in a car application, it is possible to use a flatshifter system with a slipper clutch.
The only caveat is that you don't use a blipper system. Likewise, you don't heel toe when coming into corners.
The idea behind the slipper clutch is to have the engine roatation match the wheel rotation and not cause the rear wheels to lock when downshifting or worse, have the gearbox explode due to the momentum carried by the wheels. This is why you can't use the blipper system provided with our flatshifter kit, and you can't heel toe down shift. With either of these methods, this will increase the engine speed and thus not match the engine rpm with the wheel rpm, which the slipper clutch is designed to do. It will cause a problem and defeat the object of the slipper clutch.
When you first use the slipper clutch, it will sound horrendous - don't worry, this is just the slipper clutch doing it's job.
In theory, it's possible for you to put the car into 1st gear into a corner at 100mph and the slipper clutch will attempt to match the engine speed and wheel speed for you. As I said, in theory, though probably wouldn't recommend it.
So what does this mean?
You can now drive the bike engine car like a car engine car.
Without the slipper clutch in a bike engine car, you can't down shift through the gearbox like you would a normal H pattern car engine, you have to change your driving style to brake hard, then change down as there is no engine braking. With the slipper clutch, you're able to do this and drive a BEC the same as a normal car.