Would there be a market for these?

I'm not an electrical engineer, but having an electro-magnet that close to the ECU could create some interesting side effects, no?

I don't imagine the field off of a 12 volt supply would be cause too much EMI. If in testing you found its field could affect any electronics, you'd simply put the pins in a metal housing; so it's not so big of an issue that can't be simply overcome.
 
Hood pins IMO although can be functional, are equally more for nostialic appearances. Now if you incorporate the magnetic system as part of an anti- theft device I think that might be more practicle.