If those speakers are 6-1/2", this must be about 36" fender to fender.
Here is an awesome lil trailer for whatever you can dream of. Perfect for a store front, car show, matching trailer to your real teardrop. All I know is it's cool!. A company made them in the 90's but there no longer in business. I converted this to current standards. It had a cassette player with two small speakers, which I changed to a face off Pioneer Cd, Mp3, with 6.5" Pioneer speakers, along with two 12 volt 12AH batteries with a voltage controller to go from 24 volts to 12 volts, to run the radio. It also has enough juice to run other things as well. It plugs into the wall to charge, so it can be ready for the park or whatever. It even has realistic brake lights, that work! There isn't any out there like this, so hurry and get it. Any questions, call me at 818-974-3695. Thank you, Daniel