BMW Z4 M: Small car, big engine struggles make hotter roadster unlikely

The cost of slotting a full-fat M engine into the new BMW Z4 has killed dreams of a followup to the Bangle-designed Z4 M. Offered as a coupe or hardtop, the original (and only) Z4 M drew on the 3.2-litre inline-six from the E46 M3. Markus Flasch, head of BMW M, says the new model would need to share its engine with the upcoming G20 M3, which would be too expensive.