I installed these on my '90 TransAm along with matching rear shocks and a new set of tires. went to the local street circuit yesterday and did a few laps. I am very satisfied with the behavior of the car. Rebound is adjustable - I set it to about halfway between the softest setting (factory ride) and maximum stiffness. It's easy to access and adjust these underhood struts, but you'll have to move the carpeting and foam padding aside to adjust the rear shocks.