Reader Letters: Aston corrections, speed limiters, Citroën brake wear and motorcycle filtering

Your correspondence this week covers Clarkson's "insults" to Aston Martin's "fine engineers", Citroën brake wear query and erratic driving.
The Sunday Times Driving Placeholder

Car clinic: Your motoring problems solved

For how long can I reasonably expect to test-drive a new car before I make a purchase? A few minutes in the company of a garrulous salesman never...