Ida may have more negative feelings about the car than I realised. Today we started with our car desense program. I thought we'd start with just hopping into the backseat and eating a salmon skin roll, something she doesn't get often and (supposedly) high value.
She started by trying to run out of the garage and then away from the house; when I finally called her back, she ran to the front step and didn't want to come into the garage. I should've stopped there. I instead asked her to hop in. Which she did, and then immediately peed, then stood there panting. :(
So, we've taken several gigantic leaps backwards. First, garage door will remain closed until she is comfortable being around the car hopping in and out of the back seat. Second, we're working on just being in the garage near the car. Then I'll essentially shape her hopping into and out of the car and use Julie Daniels's Broccoli Principle to build desire to be in the car. (The Broccoli principle worked great for our grooming station). Once she's actually eager to get into the car, we'll start very slowly with turning it on and just sitting in the garage.
We'll also work on a consent action (Ida boops the tire, she goes in the car; she doesn't boop the tire, she doesn't go in the car.