FrostHeater makes custom-fit coolant heaters for Volkswagen TDIs. This model is made specifically to fit the early A4 chassis, MkIV Jetta & Golf, model year 1999 & 2000 with engine code ALH. Manual or automatic. Not for 2001+ models. The difference between A4 models has to do with the battery cover design. Early A4 models use a two-piece top cover, with the sites and top of the battery being covered by separate pieces. This fits the two-piece design.
The FrostHeater connects to the vehicle's coolant system, heating the coolant and the engine block. Pre-warmed engines start faster and give cabin heat much more quickly.
Plug in the FrostHeater a few hours before you leave for a better start and quicker heat. Plug in for 4 hours and enjoy a fully warmed engine and instant heat in the cabin. Even better, use a heavy duty timer that turns on the FrostHeater for you.