Car-personality correlation

I am beginning to think there is a strong correlation between the size of a car and a person's overall disposition. The bigger the car the bigger the person's ego. Every time I drive my toddler from school, I have to get into the far right lane to be able to exit. Invariably, the owners of shabby rusty small old cars are the ones to wave and let me in, while the owners of the bigger shinier vehicles are the ones to glare and make sure I don't get in at all costs. I wonder why this is the case. Is this because a bigger car typically means a wealthier driver who feels entitled to a certain status, even on the road? Or, do the drivers of smaller vehicles have an affinity for other small car owners, such as myself? Any thoughts?