I agree with the comments about the dangers of the absent-minded, but I think there would be two obvious solutions to that -
1) You'd have to 'program' your new car to recognise your individual brain patterns for 'left' 'right' etc (since I'm assuming they're probably not totally identical for everyone), so I'm guessing you'd have to do it under supervision, so you literally couldn't make the car drive at something without delibaerately giving it the 'directions' to hit something'. As in, rather than you thinking 'Ooo, pretty' and the car driving at that thing, you'd have to thinlk 'Ok, left a bit. More left. Now accelerate' OMG! I hit something! Wait...
For those people who went 'homebrew' and made their own commands that 'let' them drive at whatever caught their fancy...then I guess the traffic legislation is going to get a whole lot more complicated =P
b) I'm assuming the cars are going to have to be equipped with all that laser sensing (etc) equipment to make up for humanity's lack of ability in multitasking. So that the car would stop if it was going to hit something I mean. Which would, I suppose, mean that you would technically be able to control the car with your mind, but it would be like driving with the world's most cautious instructor (who has their own set of pedals). I could forsee many people getting road-raged at their own car =D.
Edit: forgot to say, nevertheless: Awesome! Go Science! =D