VW TDI Glow Plug Harnesses. Which One Do I Need?

Here I discuss the four types of glow plug harnesses used on US model TDI motors. These are all available from www.metalmanparts.com
These are all aftermarket versions. I have both these and original VW harnesses listed on the web site.
2 wire harness https://metalmanparts.com/ols/products/glow-plug-wire-harness-a3-b4-a4-tdi-golf-jetta-new-beetle-passat-early-2-wire-028-971-766
4 wire harness https://metalmanparts.com/ols/products/glow-plug-harness-4-wire-a4-alh-tdi-golf-jetta-new-beetle-aftermarket-038-971-220-c
BEW BRM harness https://metalmanparts.com/ols/products/glow-plug-harness-a4-a5-golf-jetta-new-beetle-tdi-bew-brm-aftermarket-038-971-782-c
BHW and coolant heater harness https://metalmanparts.com/ols/products/heater-glow-plug-wire-harness-a4-golf-jetta-new-beetle-aftermarket-028-971-782-a