Have you noticed any trends in the driving habits of the owners of different car makes? I have. BMW owners tend to stand out as being in a hurry very often. When there's someone overtaking me unnecessarily or tailgating me it's quite often a BMW. BMWs tend to be driven by young to middle-aged men always in a hurry in traffic. Mercedes-Benz drivers are often elderly men whose driving habits are nothing out of the ordinary despite the fact that some Mercs out there have very powerful engines.
By the way, I have also noticed a significant difference between driving habits in Tampere and Lahti. The subset of very impatient drivers with a propensity to flip the finger or otherwise behave poorly is clearly larger in Lahti than in Tampere. Those people exist in Tampere as well but I'd say I've had the middle finger shown to me, been tailgated or honked the horn at on more occasions in the five years I've lived here than in the 22 years I had a driving license while living in Tampere. Tampere Urban Area has a population about two and a half times bigger than Lahti Urban Area. Tampere also has a clearly better educated population than Lahti. Also, I've noticed that the extremes in people's behavior are more common here in Lahti - and not just in negative ways.
I think a lot of this has to do with the fact that the larger a city you live in the smoother the social interactions tend to be in general. If you make any kind of trouble in public in a big city, you'll immediately feel the pressure of a large crowd you're forcing to re-route its way around you. And if you're of an arrogant type and think you can get away with more than other people, it is more likely that someone tougher than you is present in a more crowded place. I could feel the pressure of the crowd during my visit in London a year ago. In the London Underground and on the busy streets streams of people come and go ceaselessly. It's in nobody's interest to make a fuss and people tend to subconsciously copy the behavior of the people around them.