Admittedly, they need to stand out in a big way or the formula won't work. I'm just not sure the gullwing doors are the ticket.
The US needs a 'Ricky Bobby' to move over to F1 racing... and win. Someone the 'non-elitists' identify with and love to cheer for. With that 'leader' will come a movement. We're not short on marketing talent in the US, so if the right Ricky Bobby steps up to the plate, it could get the ball rolling.
Short of that scenario, I don't see it working.
Another thing they could work on would be to allow unprecedented access to the pits. Even if just during trials (obviously not on race day). I know people who were avid Nascar fans who have abandoned it for other forms of motorsport that haven't completely shut down pit access and fan/racer interaction. American Dads want to take their kids and show them things besides the fucking bleachers. Half the excitement of 'racing' is getting near it, and getting to talk to the teams. Even if teams just employed an extra member to act as ombudsman/Walmart greeter to chat up race fans, it would help attract a lot more fans.
It's funny to me that we have such an elitist divide over F1 in America, and in countries like Brazil it's a favorite of the vastly poorer masses. The net worth of the average Brazilian F1 fan is DWARFED by the average American NASCAR fan.
There's no economy of scale in America for F1 "Ivy League Racing". I'd love to see it work, as I greatly prefer the tech, speeds and tracks involved in F1. I hope F1 can find the humility to tap into 'what an American family wants' to grow the sport here.
Still... Keep trying.
The only problem is the median isn't very wide, and there's no center barrier either, so exposure to the oncoming traffic is a real threat if there were a problem.
Nevertheless, given the apparent excellent condition of the road surface, there shouldn't be any problems expected. Those tires are engineered (and priced) to do that over and over all day long.
Without any evidence of clear and present danger (e.g. reckless overtaking) I say good for the owner for wringing it out like God and all those German engineers intended.
Also, those honestly look like American roads, but I've not driven around in Mexico except in Baja (TJ to Ensenada and Cabo), so maybe the roads further east are more like American roads... but I doubt it. I'd bet the cost of fuel for one 225mph run that was shot stateside.
The ad, overall, could have had more impact - considering the budget.
Having formerly owned an X5 4.8i (pig in the snow due to weight and higher COG) and presently the owner of a 535xi wagon, I have my eye on the awd CTS wagon. I just wish it were available with a manual transmission. Also, the 535xi is the most competent car for snow/ice-driving I've ever owned, spanning from Suburbans/Denalis, Jeeps... to Bentley Conti GT to Audis, MB's, BMWs, etc. I grew up in W MI, and live in WY now... my 'snow/ski car' opinion is well-founded.
Keep pushing them at Cadillac. You're 95% of the way to your goal. Go the distance.