I know there's been loads of threads on this but I've not seen this specific question answered.

What's the best way to remove a thick coating of dirt? I drive some pretty crappy roads to work and the car gets caked in no time, if I just soak it and wash it off with a sponge surely that'll cause fine scratches on the paint? Maybe pressure wash the worse of it off and then clean as usual?

 

@rse, posted it in off topic, can some helpful Mod move it please?

 

You are right about the sponge thing. Try and soak it with shampoo-water mixture first then rinse it off after 3-4 mins. Using a pressure washer on heavy dirt in itself will also cause swirls to appear. Then use a sheepskin mitt instead to wash the car and not a sponge. HTH.

 

We had the same problem as the S comes down to the stables on a daily basis.

Much as we never wanted to use a jet wash MrV had no choice but to remove the layer of dirt first before washing the car. Hasn't done any harm, no unwanted scratches from trying to sponge off the dirt - and she's all shiny again

I'd just turn down the pressure a bit so it's not on full blast

 

I always spray (with hose) my car before washing it to loosen all the mud and grit that is on it. I find it is then much easier to remove. For stubborn mud hot water can help, but with a silverstone you don't see swirling so its much easier.

 

thanks all I'm hoping for a decent day tomorrow so I can spend a good few hours on it (only to take it out on the road and be back to square one within 5 minutes )

There's swirl marks on it already so I'm hoping to give it a good wash, a coat of Meguiars scratch X and then a coat of Meguiars clear coat wax to finish off with, oh and I've got some BMW cleaner for the back screen too ... I think it's going to be a long day

 

If you leave it on there, eventually it will dry out and fall off by itself

 

Or I could just wait for a torrential downpour to clean the car for me

How often do you clean the roof? Mine has actually stayed quite clean looking so the last time I washed the car I ddin't bother with it, just cleaned the rear screen.

 

I usually clean the roof evry 2-3 months and then apply some 303 for protection.

 

I always pre wet with a hose before I start and leave it a few minutes to loosen the caked on crap.

Here's a bit of car cleaning heresy for you. Where do you suppose those swirl marks come from if it isn't applying and polishing off all that wax? I'm beginning to doubt the wisdom of applying car wax at all.

The last couple of times I've cleaned the car, I've washed it with warm water and washing up liquid which seems to remove any road film and restore the original lustrous colour of the paint. It also easily removes the brake dust crud from your alloy wheels.

Rinse thoroghly with a hose when finished and leave it - it dries streak-free.

Zaino schmaino!!