There is a 3rd alternative to the VW switch and the mechanical switch. A conventional 2-wire brake light switch (NAPA/Echlin SL-134) and a small relay and a little harness. Complete kit costs $33 including the switch from the maker, or $42 from PI. The relay is a "normally closed" for TL operation and opens when the brakes are applied just as the 3-wire switch functioned. Many TL owners have chosen this solution. The relay is very small and installed under the air duct and quite hidden from view. Should you need a replacement brake light switch, they're about $12.