[kcabpilot]

I'm not sure if Alfa put radios in '71 Spiders, they may have all been dealer installations. The best location for them are the outer kick panels forward of the door and down near the floor. You have to cut holes for them though but this is solid mounting structure, they are virtually invisible and produce the best sound quality. Finding a location for a sub-woofer is a bit tougher, I opted to go without, put the two best coax speakers you can in the kick panels and you'll get a pretty good sound but it's a Spider so wind and road noise are going to trump just about anything once you get over 60 mph.