Smits, first of all, congratulations on the new car and welcome to the forum. The code could be from something as simple as the gas cap not tightened properly or a faulty gas cap. I'd start there and check all the vacuum lines around the charcoal canister and under the hood. Clear the code, disconnect the battery and let everything reset (you might have to reconfigure the window auto up and down feature after doing this). Then run the car as you normally would for a few days and check it again.
As to your question of someone doing something to prevent the CEL from going on when there's a code. I had a 1993 SR5 Toyota pick up that ran great. Then one day somewhere around 180k the CEL kicked on. After disconnecting the battery, the CEL turned off and didn't turn on again. When I went to get a smog check, the shop told me that it failed because of a code. After some tests, the shop verified that I had a burned exhaust valve. Code was there, problem was there, CEL light was not on.
It would be hard to prove that the dealer intentionally did that to cover up a code. Does your state require the seller to be responsible for the vehicle to be smog compliant at the time of sale? As a dealer, they may be responsible for making it compliant. You might want to look into that. BTW, I see no problem stating the dealers name when all you had was an inquiry and not a direct accusation. It's like asking, "I paid 11k for it, did the dealer rip me off?"
Good luck and hope its not like what The Josh went through.
Emissions Issues and a Incompetent Dealer
Edit: Didn't see your updated post about the gas cap. Glad everything turned out.