The new, carbon-free throttle-body partially solved the neck-snapping launches, but the problem still remained, though to a lesser extent. In addition, the car would chug a little while backing up. This led me to suspect worn universal joints or a misalignment of driveline angles. With the car on our lift, I inspected the driveshaft and rear suspension. One of the lower trailing arms was caved in slightly, hopefully during some dramatic Code 3 car chase. I also measured the driveshaft runout, which was way out of spec at nearly 0.050 inch.