AJ Allmendinger hasn't spent the last two-plus seasons trying to prove himself on NASCAR's top circuit to bail out now.

Sure, having to race his way onto the grid week after week can get tiring. Yes, it's difficult living on Sprint Cup's perpetual bubble.

Yet there's no place the 27-year-old would rather be. Not Formula 1. Not IndyCar. Give the affable California kid a decent Cup car and he'll take his chances.

"I believe that this is the toughest racing series in the world," he said. "I haven't worked this hard for two years to go out there and give up on it."

Maybe, but he might not have a choice.

The driver of the No. 44 Dodge for Richard Petty Motorsports heads to Las Vegas this week a solid 13th in points but still in search for a sponsor with deep enough pockets to pick his team up for a full season.

"Ultimately, yeah, we'd like to have that $15 million sponsorship that gets us through the whole season," he said. "But if we can just piece together race by race and keep having good finishes, I'm confident we're going to get a couple of companies to step up."

The window is closing. Allmendinger signed an eight-race deal with revamped RPM — a hybrid of Gillett Evernham and Petty Enterprises — following a tumultuous offseason when he appeared poised to inherit Elliott Sadler's ride in the No. 19 car before team officials backed off and let Sadler keep his job.

By the time the deal fell through, all the former Red Bull Racing regular had left was the part-time gig in the No. 44. He made the field for the Daytona 500 through the 150-mile qualifying race.