If you have access to a rotary buffer and a light touch, do a rough cut/fine cut rotary polish. I just did it to my '00 4Runner I just bought. The paint had quite a bit of oxidation and scratches. I started with clay bar, since I suspected the vehicle sat outside much of it's life (pulls the sap, enviromental fallout, etc. off of the paint, ALWAYS use a lubricant when clay bar-ing), then did a rough cut with some 3M polish and foam pad, then a fine cut with a softer pad, then macguier's gold class paste wax. It turned out very well, really brought back a good hard shine. It takes some time and effort, but if you have the patience to do it, it makes a huge difference. Just remember to finish it of with wax to protect all the hard work you just put into your paint!