YOU know how it is. You're driving down a dark country lane and really need to put your main beam on but you can't because there is a car ahead of you.
Not only is it irritating but it can also be dangerous, particularly if it goes on for some time and you are tempted to overtake.
If you drive one of the new Audi A8 models, however, you will not suffer such temptation, thanks to the new MatrixBeam lighting system. The new system uses 25 LEDs per headlamp and any number can be switched off independently depending upon the situation.
In simple terms it means that the headlamps will light the road ahead while closing down the LEDs which would normally be shining on the car in front of you, so you get to see where you are going without blinding the other driver. Clever stuff.
But it doesn't stop there. Using information from its sat nav system the car acts on route data to be ready to light up corners and junctions as you approach them so you can see exactly where you are going.
The latest A8 - Audi's luxury flagship saloon - was introduced at the start of the year and hi-tech additions apart has undergone a few cosmetic changes to make it look that little bit sleeker while still remaining its traditionally understated appearance.
There's been some subtle reshaping of the bonnet, the grille and the bumper, although to be honest you have to look close to pick up on them. At the back end the tail lamps have been re-designed and the car has additional chrome features as well as high gloss black window surrounds which mark it out from its predecessor.
On the inside the A8 is like a gentleman's club on wheels - with a nice mix of leather and wood. Leather in terms of the superb leather seating while the wood comes in the form of wooden inserts on the doors and dashboard.
And like in a gentleman's club there is plenty of space to relax and stretch out. The A8 is a large car and even with five people inside always has a feeling of spaciousness.
It's bristling with nice touches like four-zone climate control, a head up display (a £1,340 optional extra) and ambient lighting in the form of narrow strip lighting along each side of the car which gives just enough light to discreetly illuminate the interior while not acting as a distraction for the driver. But it's nice to see that amongst all the hi-tech features the A8 has retained its tiny analogue clock in the centre of the dashboard.
With 3.0-litres, six cylinders and eight gears in the automatic gearbox this quattro puts the power down in a superbly smooth and refined way. The big car just surges forward in silence and you dip your right foot.
And it's not too bad on fuel either, with Audi claiming an average of almost 48 miles per gallon. And while the best I could get over a week's driving was 36mpg that's reasonable for a car of this size.
And despite its size it's remarkably agile and nimble, not to mention easy to park.
If you looking to personalise your A8 the world is your oyster. The basic price of the car is just over £60,000 but my test car was priced at just over £70,000 because of the features it had on board, including power door closing at £460 and digital tv reception at £1,000.
So if you want to travel in luxury in a vehicle which also scores highly in the performance stakes but whose looks don't advertise it, the A8 could just be the car for you.