S7 is not based on anyone elses production vehicle. The S7 won four different GT championships in 2001 and has broken records at the prestigious 24-Hour Le Mans race.
Saleen operated an assembly plant (Saleen Special Vehicles) in Troy, Michigan where it conducted assembly and painting for the Ford GT for Ford Motor Company and temporarily offered prototyping and show-car building services to other automotive OEMs.
So, they would seem to have more capability than you give them credit for.
Electric S7 would be cool. I am all for more manufacturers copying Tesla's lead in this segment. It adds legitimacy. Lots of rednecks like Salleen. If they see Salleen make electrics it will lend credibility to electrics among that demographic.