UPDATE

I looked at a spare hood from a 96 SL 500 that has a cut hose. The hose has 2 wires molded into it. One is a Black / Blue tracer copper wire. The other is a spiral wound flat conductor, this is the heater.

Splicing the copper is easy, the heater will be more difficult id expect that it does not lend it self to soldering. And the flat conductor is very small.