It doesn't matter how many cars people own. They can only drive one at a time.
DH has the big family car and his 'toy' car, a very old model of the marque he is devoted to and which went out of business over 10 years ago, as I said, he cannot drive both at once and if he chooses to invest a couple of hundred pounds in a very old car to feel nostalgic about, why shouldn't he?
One of the problems with car sharing is that the interior has to be kept clean and free from any personalisation. In my case, water bottle, paper hankies, gloves, sunglasses, road atlas, of my chosen format, box of tools in the back, car park change, oh and a spare plastic fork. Anyone using it will adjust the seat, mirrors and, with my car, possibly the steering wheel, not to mention retuning the radio.
I recently replaced my car after someone wrote my previous car off in an accident. It has taken me the better part of six weeks to fully get the car adjusted to my maximum comfort and for safe driving.
Some people, and I am one, have difficulty adjusting to driving unfamiliar cars. As I said it has taken me 6 weeks to be fully au fait with my car. During which time I had a flat battery caused by taking the ignition key out incorrectly and stalled at a junction and could not restart the car for over 5 minutes because I did not know I had to depress the clutch first before restarting.
The idea of sharing sounds wonderful, if, for example, all the cars are the same make and model, and people are happy that children's car seats all fit in exactly the same way.
With tools everyone is agreed on which drill, chain saw, lawn mower they use, but all these tools offer an endless range of sizes, power and extras and different people are looking for different features.
For example in the last 5 years we have bought 2 lawn mowers, one petrol driven, one with a battery which were well reviewed and seemed to do everything we wanted, but when we got them, proved totally unsuitable for our purposes. So we had to sell them and buy different makes and models.
Anyway Hire Shops are so good and the range of tools they offer so extensive plus they have full trained staff who service and check everything when it is returned, and I would feel far safer with them.
I am not against sharing. When I was pregnant the street I lived in had a communal wardrobe of maternity wear, but I think these schemes have to be either small and personal or large scale to work efficiently and safely, and for me, safety would be a constant concern.