Despite record deliveries in the U.S., tight supplies cost Audi of America sales of several thousand units last year, its top executive says.

And while a weakened euro and struggling European economy could free up additional capacity this year, some component constraints likely will continue to put a crimp in the vehicle pipeline to North America.

Last year, the brand sold 117,561 vehicles in the U.S., up 15.7% from 2010 levels and easily outpacing the industry’s overall 10.2% light-vehicle gain, according to WardsAuto data.

But the marque could have done even better, contends Audi of America President Johan de Nysschen.

“We’ve been struggling to keep up with demand for the last two and a half years,” he says in an interview. “There is no doubt in my mind we lost some business last year. Frankly, I would say we probably could have done 125,000 units with normal inventory.”

This year, Audi is forecasting industry sales to swell to 13.7 million units, a 7.3% gain on 2011. De Nysschen expects the brand to at least hold onto its 9.5% stake in the luxury-vehicle market, which he forecasts at 1,374,000 units (excluding Cadillac and Lincoln).

That would take Audi sales to 130,500 or more cars and trucks, but getting additional supply won’t be easy.

Audi has been averaging about 30 days’ supply over the past 18 months. The Q5 and Q7 cross/utility vehicles are particularly tough to find, with stocks hovering at a 12-14 days’ supply.

“The time it takes to get the cars off the boat, to clear customs, to get on to trucks and to dealers all over the country, that’s 11 days. If you have a 12-day supply, that means the cars are basically just running through,” de Nysschen says.

“And the TDI (diesel) models, both Q7 and A3, every one we could lay our hands on we could sell.”

There may be an upside for Audi of America in the expected slowdown in the European market, as well as other markets, such as China, he admits.

“However, there’s a caveat. The constraint hasn’t been just at the Audi factories, it (also) has been with our suppliers,” de Nysschen says, pointing to such things as all-season tires and the 8-speed automatic transmissions sourced from specialist ZF for quattro models sold in the U.S.

“So it doesn’t necessarily follow that just because (Audi) factory space frees up we can switch it for the U.S. These things are being investigated.”

On the plus side, the product shortage means dealers have been able to keep a lid on inventory costs, boosting their average return on sales to 3.4%, the importer says.

“Our used-car business also grew quite dramatically, by 7,000 units,” de Nysschen says. “That was the strongest growth of anyone in the premium-brand business…partially (because) people couldn’t get the new cars, so they were buying the next best thing.”

Audi also has been successful with its year-old strategy to move up-market. With the recent introductions of the new A8, A6 and A7 and continued strong demand for the Q7, 28% of Audi’s sales now come from high-end models, up from 15% a few years ago.

In 2006, Audi ranked only seventh among brands cross-shopped by BMW buyers prior to purchasing, the executive notes.

“That’s like saying they would just about buy anything other than an Audi,” he says. Today, Audi is “the very next brand of choice,” and its share of the D-segment has gone from almost zero to 11%.

“That begins to change your driver profile,” de Nysschen says. “We now have a strategy to build a second core around these high-end models to elevate the center of gravity of the brand.”