top hat
n.— «For Nitro, the Liberty platform got a stretch and a new body, or what the industry calls a top hat, as a quick and inexpensive change. Nitro is built on a 108.3-inch wheelbase and is 178.8 inches long overall, which makes it slightly larger than the Liberty at 104.3 inches and 174.4 inches respectively.» —“Nitro concept may be headed for production” by Jim Mateja Detroit Free Press (Mich.) Feb. 24, 2005. (source: Double-Tongued Dictionary)