I don't have PP, but did install a complete set of gauges from an 05 Outback into my project Supra. Both speedos shared the signal from the single Airmar cable on the new paddlewheel. Mine was aftermarket (not PP) & had stripped leads that I spliced into the speedos.

If you don't want to cut the Airmar cable, just get the male and female Deutch connectors and make your own Y-adapter.