It’s press day at the British Motor Show tomorrow – and tens of thousands of people will be going to the ExCel centre in east London over the next couple of weeks to catch the excitement of seeing the newest and shiniest cars parked under bright lights.

Q5c There are going to be some great cars there – and some major international show debuts. But there are also going to be some major gaps in the line-up thanks to those manufacturers who, for whatever reason, don’t think that the British International Motor Show is worthy of their support.

Looking to make your mind up over the controversial BMW X6? Tough: despite attending two years ago, BMW won’t be there.

Nor will you get a chance to see the Audi Q5, despite the fact that Britain is set to be one of its biggest markets. Why not? Because Audi says the Goodwood Festival of Speed is a better place for it to spend its marketing budget. You’ll look in vain for any of Chrysler’s products, too. Although not seeing the Sebring is hardly going to ruin your day.

But Rolls-Royce is a British brand – making its decision not to take a stand at the show even more disappointing. So no chance to experience the amazing ‘starlight’ headlining in the new Phantom Coupe, then.

No Skoda, either. The Czechs are denying you the opportunity to see the new Superb’s clever rear tailgate, citing budget restraints. Is it a hatch? Is it a saloon? You won’t be able to decide.

And what about Porsche? Considering the fuss it made about the £25 congestion charge you’d think Porsche would be all over the a major motor show in London. Not so: and no chance for the city boys to have a good pore over the facelifted 911.

And the final entrants in the hall of shame are Fiat, Volvo and Volkswagen – so no 500 Abarth, XC60 or Up!

Why aren’t these manufacturers making more of an effort in what remains one of their biggest markets? Or is their non-attendance understandable because, frankly, the London motor show isn't a big enough deal and doesn't justify the car maker's outlay?

They're questions worth considering next time you find yourself in the market for a new car.