Genuine Audi - Coil Spring Insulator - Rear - Upper - TT Mk1 1.8T FWDGenuine Audi coil spring insulator rear upper for the Mk1 TT FWD. Your coil springs are not especially prone to failure, but if they have been cut, clamped, or heated to have the vehicle lowered, your Mk1 Audi TT might benefit from replacing the strut springs, be sure to replace the coil spring insulators as well. Excessive rust can make the springs more prone to failure.