We're not sure if an illuminated WiFi-detector window decal is more or less nerdy than the illuminated WiFi-detector T-shirt
, but it's certainly cooler. The shirt costs about $20 now, and the mod to take the electroluminescent WiFi signal detector panel, add the necessary power converter and mount it all to the back your car of seems easy enough if you're the type to tinker. Now -- who's going to do this, set up a MiFi, and start charging fellow commuters for access? Video after the break.