The BMW M1 went out of production in 1981 but history could have been different if Alpina got involved.
According to company founder Burkard Bovensiepen, BMW approached them and asked if they would be interested in continuing to produce the model. As Bovensiepen explained to Car & Driver, the company looked into the idea and created a list of changes that would be necessary to make the model competitive.
The biggest change Alpina wanted was to increase the car's wheelbase as Bovensiepen contends the cockpit was too cramped as the car was originally designed for racing. As he told the magazine, “It didn’t really take the passengers’ requirements and everyday drivability into account."
Alpina would also have to use one of their own engines which would have required modifications to the architecture as well as the creation of an improved cooling system.
In the end, Alpina decided against building the M1. Given the costs and number of changes needed, it's not difficult to understand why.
Interestingly, the story doesn't end there as Alpina "briefly" considered building a production version of the Italdesign Nazca C2 concept which featured an Alpina-tuned BMW V12 engine. However, Bovensiepen says the company determined the model would cost approximately 600,000 deutsche marks and "Nobody would have paid that much even then."
Source: Car & Driver