Rumble seats, commonly referred to as jump seats or mother-in-law seats, were once a popular feature in cars during the early 20th century. These seats were typically located outside the main cabin, at the back of the car and were often utilized to seat additional passengers. Some other synonyms for rumble seats include dickie seats, auxiliary seats, and folding seats. While modern cars don't typically feature rumble seats, vintage car collectors often seek them out as they represent an important piece of automotive history. Although not as commonly used nowadays, the term "rumble seat" still evokes nostalgia for a bygone era of travel and automotive culture.