The big flagship that will attempt to champion and/or save American luxury, which we've heard is called the Cadillac LTS, is all set to go into production late next year. But to meet that timetable, it's got to undergo a lot of testing. So here it is doing some high altitude work.

Spotted on Mount Evans in Colorado by reader Steve, the LTS may or may not be a return to proper glory for the Cadillac brand, now that it's begun the final stage of a decade-plus long push to global relevance in the luxury market. As I said before, taking on cars like the Mercedes S-Class, BMW 7-Series, and Audi A8 is a huge gamble for GM. Do it right, and a reputation for swift, quality, solid American luxury can hold for years.

Do it wrong, and well, um, Cadillac Catera.

But it looks to be shaping up properly. The wheelbase is stretched long and low, as it should be, and it looks like it'll have acres of rear leg room. And from what we can see of the interior, it's got a thick-rimmed steering wheel trimmed with bits of aluminum, which is a nice touch.

Up front, it's got the Cadillac vertical headlamps that have been swept back ever since the launch of the most recent Cadillac CTS, and which have continued on the ATS and the new Escalade. Plus that hood looks to be stepped up pretty sharply, too.

But really, I'm probably more excited about this car than any other over the next 18 months or so. It has the potential to be great, amazing, luxuriant and special, or really just another sad dealbreaker.

Based on the latest Cadillacs, I'm betting it's the former.