It does not sound like a very pleasant experience at all.
It being a new vehicle (and not mistreated by you) I might look at at the possibility that maybe something in the exhaust system maybe could have been damaged somehow at some point.
Such as the pipe(s) could have gotten kinked or squished and is now restricting the exhaust system.
Other than that, one might share the fascinating experience you posted at the beginning of this post with other prospective kia buyers in the showroom or out on the dealerships lot. Sometimes a little rattling of the cage might work better than going crazy, getting into a hollering match and being thrown off of the property.
You might also try calling further up the chain for help.
Last of all, if you can get your money back, check out the Jeep place, they have always done well, starting in 1941 kicking butt during WWII!
Sunday, October 20th, 2019 AT 2:13 PM