Almost half of UK business people do their most productive work during the journey to and from work, according to research.
The poll of more than 1,000 executives found that 51% of their office time is spent dealing with unnecessary e-mails and phone calls.
This means office workers are wasting more than 960 working hours each year at a total cost to the UK of £140bn.
And three in four executives say they have suffered stress or rage due to the overload of internal distractions.
Car manufacturer Cadillac released the data to mark the launch of its new Backseat Boardroom initiative, which describes chauffeured Cadillacs as ‘mobile think spaces’.
A spokesman said: “In today’s business world, time is probably the most precious commodity. Being caught up in unnecessary internal communication, which takes hours to deal with, is a frustrating distraction.
“We know the inertia of travelling helps stimulate creative thinking, so by offering business people the opportunity to get away from their desks and into a luxury mobile meeting room, we’re hoping we can help increase their productivity.”