If they turn off all the systems when not in use then when you get back into the car all the clocks show a flashing 00:00 on the display

Seriously - the clock can run off a button cell. The one in my mum's car was a duffer!

Why not have a main drive battery and then an auxillary for other systems. Make the auxillary suitable for complete discharge.

Why not have a proper off switch. One that stops the car from draining any juice from the battery?

I would say that unlike a luxury petrol car, you obviously do need to keep a battery based car moving and the electrons in the batteries active to ensure that they don’t brick out on you. Maybe a luxury sports car isn’t the best model for batteries. Maybe hydrogen would have been the better fuel choice here.

Why not have an automatic cut-off, that at, say 5%, it sends an SMS/e-mail to the owner or Tesla, then warns the user to pull over, before physically disconnecting... A bit embarassing on the side of the M25, but better than a 45K repair bill.

I think more than anything that this goes to show that battery power is not something that is going to be settled on.

If electric cars are going to be the future (if) then we'll need to advance onto Hydrogen fuel cells or something else before they become mainstream. Hydrogen is probably more expensive (carbon-wise) to produce than batteries so maybe we need something else not yet invented.

Horses?

Although I hear they do produce a lot of greenhouse gases...

And greenhouse fertiliser

If my diesel runs out of fuel. I have to get it towed to the dealer, according to the handbook. If I don't, I'll be a grand or so out of pocket for a new catalyser...

Diesel engines need to be primed, so, yes, if you run out of fuel, you need to have the system set up again.

I saw a video somewhere, possibly on TV here, about catalysers and diesel cars. For them to work properly, they have to be “regenerated” - so if you use your car for short journeys, your catalyser will never go through that cycle. You need to run the car at speeds over 40mph for a certain amount of time.

Here’s a reference:
http://www.bbc.co.uk/blogs/x-ray/2011/1 ... emma.shtml

That's the diesel particulate filter, that does that.

As Tombolt said, that is particulate filter. The Toyota 2.2 D-Cat also has a catalytic convertor. That will be irreperably damaged, if the fuel runs out and you try and restart, according to the handbook.