Re BSA Dandy, BSA Beagle, Raleigh RM's etc., these were AWFUL things! Defunct before they came off the line, they were a nightmare to sort out in the Worklshop as they were abused and built of poor quality, poorly thought out parts. These machines arose from the transitional period in the 50's when mass transport was being sought, but people had little cash to do so. The ubiquitous Motorbike & sidecar, (usually a single cylinder, sidevalve Ariel VB, BSA M series, Panther, or similar, hitched to the Busmar or GIANT Canterbury Carmobile), was still popular but could be costly.
The Japanese were some years off producing the 'Cub' 50cc scooterette, and most Eouropean offerings were 'odd' (Like the French Velomoteur). A lot of Manufacturers went into this market, James & Excelsior in Greet, BSA, Triumph with the TINA T10 Scooter, and DMW and others into Scooters. The Italians soon had the 100cc - 200 cc Scooter market sorted, but our (UK) factories continued up the blind alley with the Dandy and others.
One has to understand the total lack of understanding of the two-wheel user that existed in Armoury Road back then. If you can, read "The Giants of Small Heath" or "Whatever happened to the British Motorcycle Industry". By the time you get to the Dockers and their Champagne lifestyles, funded by "Dirty, smelly, dangerous motorbikes" you can see where the rot had come from. That this total lack of foresight and valuing key personnel still exists in many Industries today is why B'ham is no longer the World leader in manufacturing it once was.
Thus, by the time of the Dandy, the UK was ripe for Alc Issigoniss's Mini. The Riley Elf & Wolesley Hornet, Fiat 500, etc., soon saw off the Sidecar, and it wasn't until the mid 70's that the new Japanese "Superbikes" rejuvenated the stagnating Motorcycle Trade. 40 years on, and the new breed of 'Plastic Rockets' and 'Harley Lookalikes' have repopulated the roads. The 50cc 'Twist & Go' scooters have succeeded where the Dandy failed. The Dandy - Good idea, but lack of design appeal.