PTV forum member Reeko_8197 spotted Silverliner IV #280 with a LED sign. The sign resembles the exact same units that are mounted on the rear of the New Flyer hybrid buses. Over the year 280 was chosen to test out the new wireless recievers for the new Silverliner Vs which is expected to be delievered over the next 2 years. 280 also had an interesting device mounted on the on the top left corner of the car.
Reeko_8197 spotted 280 today at Suburban station
http://philadelphiatransitforums.cjb.net/topic/7223088/3/#new