the problem is, they don't publish how many people entered.
it's also a game of skill so not governed by the gaming and lotteries commission to any real degree.
i would bet big money on the fact that the payout would be less than %1.
but yes, i have played a good few times and only really come close a couple of times. i have however seen a game where about 20 people chose correctly. they got £200 in game credit. apart from 1 person who got the car.
to be honest you're better off going to a casino and staking the money on a number 3-4 times.