I agree and disagree. Certainly flex is an integral part of touring cars, but flex does not gain traction. It gains you compliance. Traction is a result of a chemical reaction between the tyre and the surface. That cannot be changed by flex.

For example, 2 identical TCX's but one has a flexible top deck the other as a stiff top deck. They will both have equal traction of the start line. In the turn it is the car that maximizes the potential slip angle of the tyre that will corner faster.

Flex allows us to achieve balance quickly.

Playing about with the top decks of cars is a very inexpensive way of dialing the car to the track and your driving style and is highly recommended to all racers.