It's a mystery

For some reason whenever we take Squiggles in a taxi (which I'll admit isn't very often since we have our own car), she starts crying and won't stop until we get out, when she will tearfully wave goodbye to the cab driver. The same thing happened when my mom took her in an estate agent's car yesterday when they went house hunting. She wailed the entire time she was in the car and stopped only when they reached their destination.

Now, she likes going in the car i.e. our car. And she is also very comfortable in my parents' car. And when she spots other cars on the road, she excitedly keeps repeating 'Caaaar, Caaar'. So, its left me baffled as to why she has this peculiar reaction to other people's cars. And she's always been with one of us in our laps, when she's been in someone else's car. Maybe it's the strangeness. On the other hand, she loves going by bus. She doesn't have the same anxiety attack when we take her in the bus, which is more crowded and bigger.

Anyone else faced something like this before? I'm trying to puzzle this one out.