Can't think of the movie- please help (Silliness 6)

There was a movie I saw from around 1970 where a guy met a Satanic witch girl at a lake. He drove a a red Ford Maverick with a Grabber hood and the girl's dad made some pretty bad ass cider. Grandma was pretty creepy and was hidden in a separate room like .....well....someone not meant to socialize with guests. Can anyone help with that?

(I actually know the movie and bonus points if you figure it out) MST3K is your friend.

This topic is to mock those assholes who ask for help figuring out a movie and when you check their profiles, they are pretty scant, thus suspicious.

Chime in with some good deliberate trolling!