Marketing options
I think we should have (in the Tycoon part) extensive marketing options.
Advertisement: Plain and simple ads on TV, radio, newspaper, magazines, internet. It affects brand awareness. You will need to adjust your ads for each region and don't forget to catch up with the latest technology.
Specific marketing: Sometimes is not just about making your cars well known. You should be able to do advertisement based on a key feature of your car. For example sports, safety, budget, offroad ... However some of those can also have negative effects, for example your a car with lots of sport oriented ads won't be as popular as a family car.
Museum: Only available if your brand is at least 25 years old or such.
Track sponsoring: Nothing is more effective than putting your brand name in a famous track.
Oldtimer support: If you invest on those options your classic cars will have a better chance to become a legend!
[bAftermarket/tuning:[/b] If you invest here, some cars will be more desirable among the tuner crew.
Merchandising: Putting your brand logo into all kinds of stuff can't be a bad idea, right?