Soren,

In the U.S. market, there's no high-low relay. The lights are wired through the switch and a button on the floor to switch beams. Only in the past several years has it become common to convert them to the turn signal stalk with a relay.

Even then, if higher wattage bulbs are installed, we usually use additional power relays.

Here's the "ultimate" article Ron mentioned (actually not by me, and not ultimate at all -- we don't cover the stalk conversion):

http://www.vclassics.com/archive/relays.htm