Dimensions for I can't go back to 1989 but I do have the info on the 1990 which I belive was identical. You are right in that the new Civic is almost as big. The new Civic is about 8 inchhes shorter but it is 1" wider and 2" higher. They are very comprable in size.here's the specs from the service manuals1990 Accord--2 and 4 door
verall length 184.8 inches (4695 mm)width 67.9 inches (1725 mm)height 54.7 inches (1390 mm)2006 Civic 4-door Overall length 176.7Width 69.0Height 56.5hope that helps