Put the Drop Stop in that category. The Drop Stop is nothing more than a piece of black neoprene that fits over a seat belt buckle and fills the gap between the driver or front passenger seat and the center console. It then moves with the seat to prevent cell phones, loose change, french fries, or any number of small, loose items from falling through the cracks. One size, apparently, fits all cars.
As someone who has spent at least 25 minutes of his life hunting for his cell phone under the car seat, I can’t say I’m not a little intrigued, but $19.95 (“An incredible $60 value for only $19.95!”) may be a little steep for a couple pieces of foam.
Fits Any Size Car Seat Crack! (Gizmodo)