Installing a strut tower brace stiffened up the front of the chassis nicely, but what can I do about the rear? Is there a brace for the rear of the car that will yield a similar effect as the strut tower brace did in the front? I am tired of feeling the car flex every time I drive down a bumpy road. I plan on installing a 4 point rollbar in the upcoming spring, and I bet that will help, but what else is available?