Probably caused by the builders van/4x4 that went through before you, leaving a building site embedded in the brushes especially for you.

NEVER use an automated car wash unless you dont mind the the brushed aluminium type finish!!

You will probably find a little notice stick up somewhere "Customers use this car wash at their own risk......"

And mechanised car wash brushes are known to leave marks - which is why many avoid them.

Not always the case:

I recall - a few years ago, a UK TV motoring programme (possibly Fifth Gear) conducted a test to determine the best/worst methods of car washing. They assessed hand washing with sponge, rotary machine, drive-in road side washes and hot-brush manual washes. The rotary brush machines did suprisingly well, due to the centrifugal action of the spinning brushes causing dust/dirt to be flung off the brushes, and keeping them relatively clean. The roadside gangs faired poorly due to the risk of dirt contamination on their sponges/clothes. The hot-brush washes were the worst, as the brushes are often left on the floor, and they can be used dry, after the flow of water has stopped.

I use a local rotary machine car wash (Tesco petrol station), and have done occasioanlly for a few years, with good results. I see a variety of top-end motors using it (Mercs, Beemers etc.)

The advice has always been: fold the wing mirrors in and remove the radio aerial. My car also has plenty of wax on it which might help!

Agreed. And the machines are no cheaper than the hard-working East Europeans in most towns who do a much better job without the risk of scratching.

And I do like Brum's explanation of the term 'brushed aluminium'!

Round my way, the hand wash quality is very variable - a few of them thing nothing of dropping the sponge on the ground and then carrying on, oblivious to all the grit they picked up and then "apply" to the car.

Agreed. And the machines are no cheaper than the hard-working East Europeans in most towns who do a much better job without the risk of scratching.

Lots of risk of scratching - all they need to do is drop a cloth and pick it up and keep using it or not rinse out properly or be weraing some jewelery on their hand/wrist which can scratch...a long way from being risk free.