Back in the 1920's and 30's there was a short shotgun called the "Auto Burglar". It was a pistol gripped side-by-side shotgun with about 10" to 12" barrels. The main purpose was an effective gun against car thieves who could (then) jump on the running boards armed with guns or knives to car jack you. Made in 12, 20 and (I'm told) 28 gauge, these were nasty little critters to face -- or to use inside a car. But very effective!
I think the Auto Burglars are classified as an AOW by the feds and prohibited in many states. Someone told me they were going to be reclassified as a C&R piece, but I haven't confirmed that yet.