It's never bothered me, the implication of what happened is more effective and creepy than explicit gore. For example, just the brief shot of Buddy's burning body fall to the ground is far more effective than some prolonged grisly demise. You also don't need to see Moochie cut in half, Arnie's lack of reaction when told about it is much better storytelling.

When the garage owner went and sat inside Christine and the car killed him by smushing him against the steering wheel, there is a scene where a bunch of blood comes out of his mouth into the front window as he is being crushed.

Yea, there was a shocking lack of gore in this film. I think the only bloody scene was Arnie's death. And not much of it at that.
I can only guess they wanted a PG rating. Carpenter certainly isn't shy using blood in his films.