Heater Idea

[beetle1303]

Here is THE question:
Assuming that your engine has j-tubes (ie no heat exchangers for keeping you warm in the winter), what would you use as a heat source?

except an eberspacher heater...( they quoted me 800 euros just for the kit, so its out of the question)
Actually an eberspacher unit will be my veeeeeery last opion as i would like to be more creative... and i dont like the idea of going through another winter without a heater...

Chris