straight plate
n.— «After the hearing, Ricketts said that van operators should be given more leeway when it comes to bus routes, because abiding by the rule forces commuter vans to residential streets and makes it easier for illegal vans, or as he calls them “straight plates,” to operate.» —“Liu Wants Change For a Dollar (Van)” by Shane Miller Queens Ledger (New York City) Apr. 6, 2006. (source: Double-Tongued Dictionary)