In return for the MINI underpinnings, Toyota would give BMW access to the iQ platform which they would likely use for the upcoming i-Setta electric car.
While details are lacking, the proposed product sharing agreement would allow BMW and Toyota to cut costs while gaining new, fuel efficient vehicles. In return for the MINI underpinnings, Toyota would give BMW access to the iQ platform. BMW would likely use the iQ to underpin their upcoming i-Setta electric car, in a similar fashion to Aston Martin's Cygnet Concept.
Last week, BMW's chief designer, Adrian von Hooydonk, said the MINI Coupe and Roadster could be used to underpin future BMWs. While he didn't specify which models, the likely choices seem to be the long-rumored Z2 roadster and possibly a future generation 1-Series.
It's unclear what Toyota would do with the MINI platform, but the company's new President, Akio Toyoda, has promised "cars that are fun and exciting to drive." MINI underpinnings would likely achieve the desired result, but a lot of details still need to be worked out.
The MINI Coupe and Roadster won't go into production for at least 2-3 years, so any resulting BMW and Toyota products are likely several years away.