Ditto here no-one seems to carry any more as modern cars computer electronics are easily damaged.

I stopped using leads and went over to the small lithium jump starters, which have come in extremely handy over the past three years. All of our family head to remote locations alone, so these jump starters don't mean you have to rely on help from others. Mine has been used offshore too, assisting boaties with flat batteries. Even the marine rescue carry them as they are simple to just past over to the most common breakdowns we get. Theres also the fact you can use these anywhere without having to get another vehicle parked close enough for the leads to reach, such as a busy shopping carpark etc.