Welcome to the forum. Next time you have a question, it's better to start a new thread rather than waking up an old thread on an unrelated topic.
The purpose of the red tab is to reduce the likelihood of the connection coming apart by itself. You depress the tab before pulling the connection apart. If you don't want to unplug the connection, you don't have to do anything. You can't replace only the red tab. If you want to fix it, the entire plug will have to be replaced. If you can use a pick, small screwdriver or similar tool to depress what's left of the red tab, you may be able to get the old plug out of its socket. Then you can either cut off the old plug and put on a new one by splicing individual wires or get a service replacement plug and the necessary tool to install new terminals into the replacement plug. Finding the replacement part might be difficult but that particular plug might be more or less standard and a replacement might be available on the aftermarket. You may have to search junkyards. Before you do anything, see if you can find a replacement plug. Once you have the replacement, you can decide how to proceed. If you decide to splice the wires, use crimp fittings with waterproof heat-shrink covers to keep the splices secure.

Hi,
I have a 2010 PT cruiser, and the same thing was happening. I took it to my local shop, and they replaced the batter, and then they changed some fuse wires, did a tune up, a few more things, it was still happening!!! So I took it to the dealer, and they said the draw was from the Power Seat motor!! I have to go in tomorrow, as they can't order me a new one, and he is going to set the seat up for me and unplug it. I will get back to this site if this indeed was the problem. For paying close to almost $2k in less than 2 years, this better be the reason!! I bought the car 'cause it had such low mileage, 46000, and I don't drive that much.