Details about McLaren's upcoming P11 have been trickling in over the past few months, and we have a couple of new tidbits to add to the file. The P11 program is progressing on schedule and is slated to be unveiled in the fall of 2009 with an on sale date of March 2010.

Word has it that the P11 is taking aim at the Ferrari F430 Scuderia and the Porsche GT2 and will uses a Mercedes AMG-sourced 6.3L V8 making 550 horsepower. Although the engine will be sourced from AMG, it is believed that Mahle — the company that took over Cosworth — will build the engine. That power will be sent to the rear-wheels and the car should be capable of sub-4 second 0 to 60 runs, as well as a top speed over 200 mph.

Size wise, the P11 should slot between the Audi TT and R8.

Following the launch of the P11, McLaren is expected to offer a Spider version of the P11 in March 2011.

Also on the calendar for the 2011 is an even more high-performance version of the P11 — dubbed the P12. The P12 will channel the spirit of the original McLaren F1 and, as such, will be powered by a V10 making in excess of 600 horsepower. To further push its performance to the limits, the P12's P11-based platform will be completely re-engineered to reduce as much weight as possible.

McLaren recently broke ties with Mercedes after co-creating the SLR supercar, which should clear some room in the McLaren factory just in time to start production of the P11.