Dropping puffballs on cars is very dangerous to car-owners who may swerve or emergency stop and only the terminally stupid do it.

Phallus impudicus, (technically amanita phalloides) the "stink-horn" produces and evil dark slime over the "glans" which is effective to attract flies to spread the spores.

According to all the English fungi books I have read, the only two really really dangerous fungi in the UK are amanita muscaria and amanita pantheris (the death cap and the panther cap).

Fly Agaric (the red and white spotted one) is hallucinogenic and somewhat dangerous, but so unmistakable.

No-one has mentioned "Poor Man's Beefsteak" - or "Horse Mushrooms" - or "Yellow stainers". I've never tried the first, but have eaten both the others with no ill effects (some people have different metbolisms and get very gyppy tummy from them) although I find the taste can be overpoweringly strong if you use them incautiously in stews.