“I HATE driving in Los Angeles—the traffic makes you want to shoot yourself,” says Dr Dre, a rapper. So he buys wheels from Becker Automotive Design, a Californian firm that customises rides for the rich and gridlocked. His latest purchase is a stretched Cadillac Escalade with a flat-screen television and a digital system that allows him to browse his home film library in the car. “I like to close the curtains, relax and watch Martin Scorsese films,” says Dr Dre.

Todd Doney, a property broker, used to spend three or four hours a day stuck behind the wheel of his Bentley. Now he spends that time talking to clients on the telephone, returning e-mails, and going over documents. His chauffeur-driven car is, in effect, a tricked-out mobile office. “I feel like I’m beating the system because I can work while everyone else is stuck in traffic,” he says.

For three years in a row, congestion in Los Angeles has been the worst in America. That is good news for Howard Becker, the founder of Becker Automotive. He began his business in the 1970s, installing sound systems for the Beverly Hills glitterati. Today, he customises cars and vans for clients such as Mark Wahlberg, an actor, and King Abdullah of Jordan.

The vans take up to seven months to complete and come with such features as touch-screen computers, wireless Internet, cable TV, seats for half a dozen people, bathrooms—and, in one case, an exercise bicycle welded to the floor so the owner could work out.

Becker cars are not cheap: they range from $150,000 for a basic rolling palace to more than $500,000 for an armoured one. (These are apparently popular in the Middle East and Africa, where security is a priority, as well as with nervous celebrities.) On the inside, Mr Becker’s cars can be as opulent as you like, but most customers prefer the outside to be understated. If you are a star stuck in traffic, it is unwise to advertise the fact. Who wants to be mobbed by fans on the freeway?

Two decades ago in “Let me ride”, Dr Dre boasted that his car had “16 switches” and “sounds for the bitches”, adding that he was “clockin’ all the riches”. Today, nearly 50 years old and worth $800m, he no longer feels the need to show off. “When I was younger, I wanted Ferraris and Bentleys and Rolls Royces,” he says. “But now, I’m beyond that. I just want to sit in the back of the car and relax.”