[Bimmer-Bob]

So your CA sounds like he probably wasn't aware of the audio decontenting that took place in 2010 and early 2011. It's somewhat understandable, as it was a realtively short period of the total run that US cars received the Stereo system as standard instead of the HiFi system.

However, one simply needs to sit in the car and confirm the presence or absence of the tweeters. If it's a 2010 US car, and it has no tweeters, then it has Stereo. If it does have tweeters, well then someone ponied up for Premium Sound and you in fact have Top HiFi, or somebody installed something aftermarket (possibly the Alpine retrofit as Dackel mentioned, although not super likely in the US).

However, what the car definitely does not have is HiFi. US cars of model year 2010 just didn't get it, either standard or as an option.

Something else you can do is take a look at the amp. No amp = Stereo, black amp = HiFi, silver amp = Top HiFi. The Alpine amp is also black, but it is clearly labeled as an Alpine product. I'm not sure of the markings on the other amps, but I would guess you could at least get a part number or something off of them to help ID them.