What a load of old tosh!
How does making people carry a breathtest kit in their car have any influence on the number of accidents and deaths on the road?

I carry a spare wheel (and tyre) but it doesn't stop me getting punctures now does it.
If people want to drink and drive then they will, there is no getting away from that fact, short of having a blood and breath anlyser built into the drivers seat and/or steering wheel then I don't see how it can be stopped.
Those nutters at LM who insist that they drink copious amounts of alcohol and then jump in their cars and speed off, having first bragged about their highest speeds on the peage are highly unlikely to use the breath test kit for anything other than proving to their mates how pissed they are... Now I'm all for having fun at LM, but would prefer not to be run over or driven into by some pissed yobbo.
Anyway, it just seems like a political vote winner with the safety people, and a bonus to the tax/fines income to me. Also I presume it will be some french company that makes the kits.