Sadly i can't divulge my sources, only commercially available & come "decanted" into anonymous containers. Some are great but others are'nt that special. If your paintwork needs the full works, start with T cut or a similar compound, small section at a time with an on cloth & an off cloth. If it's been left too long it's gonna be hard work. When you think you've finished then hand wax & polish it (even after a machine polish) to seal the paint & your hard work. After that just stay on top of it. Wash at least twice a week & shammy off, NEVER leave them wet EVER. Only treat your blacks (door trims, tyres etc )once a month or they build up & turn brown. I could go on for ages but the two best shop bought products i,ve found are Halfords wash & car shampoo, one capfull in a bucket of water, better than some commercial products i've tried & i still use it now, & for your interior, find a £1 shop or similar & look for "Big Orange" in a squirty bottle. It makes the interior look & smell like new without the shine or dust attracting properties of Back to black, cockpit shine, & other such wastes of money. I've divulged a few closely guarded secrets, no excuse for a filthy car, if you live in a field you can buy a hose!!!!
Sorry for the long post but i can't stand mucky motors!!!!
