my view is.. It should be compulsory for L platers to do say 10-15 hours with an instructor first before their parents/friends are allowed to 'teach' them.
And possibly they need to do a few theory lessons on the dangers and consequences of driving.
Also, from red P's to green, it should be compulsory to undertake some sort of driver training course.
If you can't afford it, you shouldn't drive.
Driving is a privilege not a right.