This is BMW's four-door 6 Series

BMW's long-awaited four-door coupe model's apparently nearing the end of its development pipeline, as newly retrieved patent images indicate. The elegant new model will be essentially a four-portal 6 Series competing with the Mercedes-Benz CLS and Audi A7.

Recent patent filings show a new model that's a dead ringer for the BMW Gran Coupé shown at the 2010 Shanghai auto show. Noted changes to the bumper, exhaust pipes and other subtleties. Other than that, as BMW execs have said, the "coupe" will be similar in content to the current 6 Series.

And the name? Don't expect to see a Gran Coupé badge on the grand "coupe" anytime soon, but an expansion of BMW's GT franchise isn't out of the question.