A is better. A means that you did not in the past but you might now or in the future which is what I think is intended. A third possibility is "I never told you that is a red car / You never told me that is a red car" which means essentially the same thing.

I'd go with the first set of options, but I would add just a tiny bit. "I've never told you that it is a red car." Just to be clear about what you are referring to. However, if the second set was rephrased to "I never tell you there is a red car" it may be correct grammar. But more context would help

A: I've never told you that is a red car. You've never told me that is a red car A is correct grammar, compared to B. However, the sentences are strange. If you give more context, I might be able to help you more.