In my humble unscientific opinion, I think you tend to notice more of the same brand that you are driving than the other brands. When I drive my Volt, I swear I could spot one in rush hour traffic going the other way hidden behind a motorhome and two semis. I also seem to notice more bow ties too. Seems to work when we are in the Jeep, too. If you drive a certain brand, at least in my experience, you are naturally going to notice more of your brand on the road. Again, completely unscientific, but it's just a natural need to belong to a group that makes you want to seek out others of your own brand.
I know I'm always eyeing the other toy haulers out on the road. :B