Good aftermarkat alternators? For imports?

Does anyone out in the modelling world make a good resin or white metal alternator? Particularly ones that look correct on import cars (ie, no fan and more round than square). I don't understand why there are all these lumps in kits and no one makes anything to replace it. I remember there is a 1:25 somewhere in one of my kits but it's way too small for 1:24, modern cars.