I don't know if it meets all the USB official specs but this charger below (made by BlitzWolf) has USB C attached cable with 3 amps and a second USB A port with 2.4 amps. I wanted a fast, reliable and standards conforming car charger with USB C. I would appreciate any feedback about this one.

http://www.amazon.com/Charger-BlitzWolf-Attached-Chromebook-Macbook/dp/B017941M8I/ref=sr_1_15?s=wireless&ie=UTF8&qid=1448053076&sr=1-15&keywords=car+charger+nexus+6p

Anyone have any experience with JOTO and their car charger? Recently popped up on Amazon. No reviews.

USB Type C Car Charger, JOTO Dual Rapid Ports Car Charger (Type-C Port 5V 3A +Quick Charge Port 5V 2.4A) Attached 3.3ft USB Type C Cable Adapter for Nexus 6P,Nexus 5X,Lumia 950 950XL,OnePlus 2

http://www.amazon.com/dp/B0179HN184/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=KWYNA3D352VO&coliid=I1NY5J6PZSWEX5

Looks like the same charger is also being branded and sold by BlitzWolf

http://www.amazon.com/dp/B017941M8I/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=KWYNA3D352VO&coliid=INZSO4NDKXEAC&psc=1