Huby,
If you are having no luck sourcing LOKAR performance from Germany, look for a tandem road bike rear brake cable and housing from your local Bicycle Shop. They are the same size (~1.7mm x 3500mm), good quality, and are multi-strand. Go with a good brand like Campagnolo or Shimano. Because of the heat in the engine compartment, stay away from anything teflon-lined, as the heat may cause issues. I grease mine once a year or use the motorcycle cable luber to force the lube down the full length of housing.