Yes Smokey, it's a matter of public record that houses are being burgled specifically to steal car keys, for the purpose of taking said cars.

I know that - the key stealing's been a commonplace method for years. Mine works the same way as yours, with a chip in the key. I was referring to the disabling of immobilisers by the vehicles' owners (who have more time to do it) for the purpose of getting round the alcohol detecting device, and the availability of the information on the internet enabling one to do so.

I recently priced a new key, by the way. £70 for a 'cheap' one made by a local locksmith re-using the old chip, and £150 - £200 for the manufacturer's own with a new chip. That's just the key.. I doubt very much if a 'foolproof' alcohol detecting device/immobiliser is going to retail at £30 - £40. At least not on Japanese cars, anyway.