I've just come back from Autobarn & bought 10amp=3mm and 15amp=4mm various colors wires. When I ask about "gauge", they dont know,they work in mm instead. Hope the 3 & 4 mm is confirm equivalent of 16 & 18 gauge over there? He said it suitable for engine/heat resistant.

I will need to find or order the fibreglass tapes (very dear $5/meter) for wirings near the engine or intake manifold.

Thanks