At Bimmerpost forums, an alleged BMW post is reporting BMW's version of the new sports car project co-developed with Toyota which will be offered in two body styles, roadster and coupe. It will wear the Z5 nameplate.

The insider is forum member "Scott26" who often breaks BMW news on the forum notes that BMW is working on a new front wheel drive Z1 roadster based on the same UKL platform as the upcoming 1-Series GT and the next Mini. In detail, here's what Scott26 mentioned:
"Many within the company wishes for an M Z4 but unfortunately the market is small. It is possible to do a limited model like the 1 Series M Coupe but there is no decision to do this. There was the plan to absorb the Z4 iS into the M Performance line but this fell through in the final hour.

We will shortly be presenting our collaboration with Toyota for a new interpretation of a new highly focused sports car first as a concept. The production car will be called the Z5 which allows us to align a new UKL (FWD) based Z1 with equivalent MINI sports car along with a mid sized Z3 (the name is coming back) which again could be aligned with Toyota. Although for some markets Toyota might use Lexus branding.

The Z5 Roadster will feature exterior and interior design from BMW, as well as BMW engines. Toyota will supply optional hybrid technology and BMW will supply CFRP in its construction. A coupe will follow.

The new "Z" design is influenced by the Vision ConnectedDrive Concept Car."