'They all want to be the celebrity who arrives in a Rolls Royce': How £1,000-a-night cars and diamante encrusted frocks have turned the British school prom into a £100million industry

With jewel-encrusted dresses that can cost up to £1,500 and

 increasingly outrageous forms of transport including supercars (main picture) and speedboats (inset) on the shopping list, proms have become an expensive business for parents. Now a new documentary has gone behind the scenes in the £100m industry to pinpoint exactly where the money goes and what's driving the urge to splurge. Prom Crazy: Frocks and Ferraris also unveils a whole new way to spend money - the extravagant 'promposal', which involves resorting to elaborate (and expensive) ploys to secure a date for the big night.