David Beierl wrote:

> I don't know how much heat the halogens produce
> compared to the regular, though I suspect it's similar.

The heat output from your 50 watt bulb is nothing similar to the regular 21 watt
bulb. The common knowledge is that only 5-20% of power is transmitted to the
light, so while your 21 watt bulb pulls 21 watts from the cars electricity, only
5 watts are used for light, the rest is wasted in heat. So, the 50 watt bulb you
have probably generates 10-15 watts of light, the rest is heat. No wonder the
rear lights melt!

Don't ask me how I know, I just do :-) Its something I picked up once, and it
stuck in my memory.

PerL
Bug, Bus 'n 'Back