Have a butchers on here mate http://www.cleanyourcar.co.uk/ they only sell the decent car care products, none of this halfords rubbish!

Id never use a normal sponge to wash it as you will have swirls everywhere after a few washes!
Use something like this http://www.cleanyourcar.co.uk/washin...e/prod_13.html only a fiver, ive got one and its millions times better than a sponge, its very very soft and thick material so it traps dirt inside and doesnt rub onto the paint work, plus it holds loads of water/soap, awesome sponge

Dry it with something like this http://www.cleanyourcar.co.uk/washin.../prod_154.html which again is a million times better than the normal leather drying affair, i dryed two cars with mine and i didnt wring it out once!, takes half the time aswell.

Both of those will mean you can wash the car without scratching your new paint work.

Anything else?