PWM replacement for car lighting dimmer

The original spec lamps for these cars are no longer available. Modern lamps of the same from factor have higher power output, which means they are brighter (yay!) but get hot enough to melt the plastic trim (doh!). I have been running LEDs for years in my one car without the dimmer. But I thought it would be nice to have the dimmer working with either LED or incandescent. High-side switching is my only option, however.