Here's what I do, it's simple and it works!
1. Use rubbing compound (Cheap)
2. Use polishing compound (Cheap)
If your not satisfied with the results after 2 above, do 1 & 2 again.
3. Use Meguiar's PlastX (About $8 - Optional)
Yesterday I did my 96 Chevy S10 P/U for the first time since new.
It took about 10 minutes and the difference in night driving was absolutely amazing. I've been doing this on my 2001 Montero for the last year and it lasts about 6 months. Some people make things too complicated.