There is a car fair at the old exhibition center (near the 2nd ring road, south side). I learnt it passing by there and reading the ads. From the 30th for a few days.

Is this a fair for dealers selling new cars?
If not I would not advise buying anything.
If it is a new car fair, go to look and collect business cards. If you do fancy a car, you can look at Chinese online websites. Cars are reviewed and you can book test drives and probably look for deals on new models. All of the dealers worth dealing with are listed on these sites.

Once you think you have chosen, then go to dealers with your bargaining head on. For most of the Chinese brands there will be multiple dealerships in Kunming. You can also see how these are rated/reviewed on the websites. There are good dealers, bad dealers and then the ugly ones.

At this car show the different brands try to compete with the others by producing the most decibels. If you go bring earplugs.

I think it costs 50rmb to get in?