hi ben, I worked in a Expensive Daewoo dealership for 9 yrs, engine mods that included changing cams, superchargers, turbo's, inlet manifold swap's, t/body swaps, etc would void your powertrain warranty. ie. engine, trans, tailshaft, diff. This was logged on an internal Expensive Daewoo website for the life of that VIN number. A turbo fitted to your car did not void an elec window problem for example, only power train. Lowering your car voided suspension, bushes and steering warranties. Changing an entire exhaust didn't void warranties as it was deemed a replacement. - worn out