How many devices (cars, external remotes, keypads, etc...) do you have connected to your garage door opener?
The reason I ask is that your memory on the opener is probably full, since it still remembers the old vehicles and such. I would look up the instructions on resetting the memory on the garage door opener and then reprogram the vehicles and the clickers that you have.
I had to do the same thing last year when I bought my truck, as I have too many devices and the garage door opener cannot remember all if the devices that I have.