Whenever, Sir, you opt for a proper bodywork do go into details for it to minimize waves in reflections. This may mean a severe primer treatment including several coats of a sandable form. Once satisfied that any sanding wouldn't bring about any metal to surface, use sanding boards of large lengths avoiding the hand sized sanding bars at all costs, until and unless, the area demands it; this act will ensure seemless cohesion in paintwork and flawless reflections. Use a guidecoat of alternate color to show highs and lows and create a finish to near perfection.
Another dillema faced during this are the door edges sunk in. Weld new sheets and prime it again or take a hammer to inner lining and pull the door edges out. If you face metal bearing, hammer in a little. Continue with another primer coat and level the finish again. Leave it to cure atleast 4 days for the primer to settle in, sand again; you will have a walking mirror.
Once again, the above is for a 'factory seemless waveless relection' at par only with base metal made with production standards.
P.S Nice to see such an honorable approach with which, Sir, you reply. I guess few left with honorable vision and virtues.