Marketing is a very important aspect for almost every product.
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?
Good ideas! 
Good idea, but don’t you think it would be easier to just generalize the catagories into smaller segments, like in Game Dev Tycoon? You would be able to select small, medium, or large marketing. For example, A small marketing campaign would be magazine interviews, and online news columns, whereas a large marketing campaign would include TV commercials, celeberty endorcements, and brand plastering everywhere.
For the general advertisement (getting your brand known) it would be ok. But I think that there’s place for more specific stuff.
Yeah, but you need to keep development time in mind. For developers, how would putting in different marketing strategies benefit their time and players time? It just seems like a little bit needless given how little it might actually affect. Different people might like your cars, but what would that effect overall? You would still get the same money.
This is still a few big updates away, but your thoughts in here pretty similar to our rough plans. More details will come up when we get closer to implementing these things 
Another idea would be a specialty market. Namely designing something like a police interceptor or a taxi. That would open the door for municipal contracts which would probably bring in less revenue-per-vehicle than normal sales, but has a guaranteed volume.