Mercedes is hitting it big with their AMG division and the BMW is starting to take notice. The BMW M division has come to terms with the fact that they will need a bespoke model to take on AMG’s SLS supercar creation, but so far, top execs aren’t buying it."From an engineering perspective, we have the skills and we’d love to do it," product development chief Albert Biermann told Autocar in a recent interview. "We’ve discussed it several times but we’ve never been able to make the business case. Everything we do has to make money."Biermann brought up one possibility in an M version for the current generation Z4: "There are days when it hurts not to have one but there was no business case at the time when the decision was taken. We are trying to make a case but there are so many factors to consider."BMW’s main focus right now is in developing alternative powertrains to move along with the greener times, such as the 1.5 liter inline 3 engine with two electric motors found in the future i8. However, if BMW wants to get in good with the supercar segment, a real M supercar is still required.