There are still some spaces on some of the trams for business owners to advertise. If you would like to put your business on the side of one, make a texture for a poster that will fit under/over the windows, such as Mr Pearse has done on the academy tram here.
Victorian fonts and designs obviously fit the town covenant best. Send the texture to me and I’ll get it slapped on a tram car. The ad space is first come first served, but if I get a lot of ads, they will get rotated out at intervals to show as many as possible :)