I interested yet skeptical that anything I could add to the coolant would help it warm up, without some sort of trade off in cooling capacity.My car used to take forever too. I bought some amsoil coolant boost and it made a huge difference. Plus I leave my heat on recirulate and fan speed on 1. I have plenty of heat after running the car for 10 mins
I can have heat in 10 minutes also, just need to head straight out onto the highway at 55mph+.