When Frank Castle's family is being killed and his wife and son are hiding under the boat, she tells the son she'll count to three and they're going to run to the Jeep. Not only do they try to get away in a Chevy Blazer (not Jeep), there isn't even a Jeep in the area.
Not a slipup. People use brand names as a generic. For example: "Xerox this." Even though you mean "Would you please put this in the copier and make me a copy?" If someone was shooting at me, I don't think I would stop to think what particular brand of vehicle I was jumping in. I would be more concerned about where the keys were.