Has anyone got any tips on how to remove those annoying scratches on cars that appear after you have parked it?

There must be cheaper ways than going for a professional paint job.

I've read that toothpaste can work and seen those ridiculous ads like Renumax (do you get that in England?) that promise the earth but apparently don't work.

I understand that scratches that penetrate the clear coat are a different animal and I din't really like using a paste that cuts the first layer of paint off.

Home remedies that might work, anyone?

Thanks in anticipation.