gp has that sporty look thing going for it, the regal is kinda plain, but the engine is the same. inside you get better seats and a more detailed dic. like actual boost #.
other then looks and the inside, its the same car really. the bonnie is pretty nice tho.
temp sensor should not be that bad, open end wrench should get it removed.
new in the box sucks, but its the truth, everyone who changes the damn thing does it 2 or 3 times till they get a working one. (parts store brands seem to be the worst)
i did a engine swap and took the one from my old engine and re used it. no way i was getting a new one for this very reason.