I think the M3 Lime Rock edition is simply BMW's answer to the less expensive, more powerful 444 horsepower Ford Mustang Boss 302 Laguna Seca.
BMW Motorsport dropped the "otorsport" from "M" many years ago. And the only real race-derived M street car was the E30 M3. One could argue the original street M1 was built to qualify it for a race series, but the series rules changed before the car made it to market so they ended up creating a fake celebrity race series just to get some of the cars on the track. So we're back to the E30 M3 as the only pure "motorsport" M car. Jalopnik is way late with its commentary.