You know I was thinking about this last night in bed, so Lotus kept the same Toyota 3.5 supercharged V6, and now partnered with AMG for their 2L turbo'd engine, as well as their dual clutch automatic. You know what I wish they had done instead, went to Audi and took one of their RS engines, either the 2.5 Turbo 5 cylinder or even the 2.9 Turbo V6. I'm assuming both would work as they aren't RWD platforms and similar to the AMG 4 cylinder. They should enough space for both as the 3.5 V6 and supercharger isn't exactly a small engine. Then they could have paired that with one of the dual clutch autos offered by Audi/VW group.
The only reason I can think why this wouldn't have worked out if the relationship that Audi has with Porsche, and the fact that the Lotus is pegged to be a direct competitor to the Cayman S.
BMW wouldn't have really been an option just because they typically use a RWD platform and the engine placement likely wouldn't have been ideal, plus again they are a direct competitor with their M2.
But that would have been pretty sweet, either that awesome near exotic sounds from the Audi 5 cylinder or the 450+Hp from the 2.9 turbo.