The curious phenomena by which men traveling in the back of large jostling vehicles (busses, vans, ect) tend to achieve spontaneous erection due initially to the jostling of the vehicle and then secondarily to the jostling of their own wood against their legs and/or pants. This erection can often be relieved only by extrication from the back seat.
Cody: Holy cow have I got a case of Back Seat Syndrome.

Matt: Boner city?

Cody: Worst ever. Switch me spots.
by Lord Azaldon April 19, 2013
Get the Back Seat Syndrome mug.
A rare condition in which one cannot decide which seat to take, even though only one actual seat is available. This is generally caused by a mental defect of some sort.
Eric: I cant decide which seat i should take on the bus sometimes. I think I may have Front seat, Back seat syndrome.
by Jim Sominsummthin July 20, 2011
Get the Front seat, Back seat syndrome mug.