Sentence:  I suspected I wouldn't care an awful lot for his companionship, so I put him and another one in the <WSD>rumble seat</WSD>, and with the other two in with me I found the trail back to the Parkway and turned south. 
Meaning of the word marked with <WSD> tags:  An extra passenger seat or row of seats in an automobile, which typically folds away into a rear storage compartment.