They wanted to work with ACPropulsion and mass produce the TZero. Both Martin and Co, and separately, Elon tried at some point. AC said no thanks but we will sell you drive units and tech. Some of the AC guys (Wally Rippel) went to Tesla. Tesla soon changed to the lotus chassis and developed their own tech. Enough changes that AC couldn’t claim copyright. Alan Cocconi at ACPropulsion was the one that was working on using Li-Ion cylindrical cells since he was using them in model airplanes IIRC.