Dmenn, what do you plan to put on the leather? I recommend the "Soffener" from
www.colorplus.com. Great stuff.
For washing/cleaning windows I recommend a mixture of Distilled Water & Denatured Alcohol. 2 parts water to 1 part d.a. Spray mixture on a clean towel, then wash window, to finish use another dry towel and buff dry. Work fast, this stuff dries fast. Not in direct sunlight.
For tires, Vinylex is great. Not too shiney.
For wheels and "leading edges" (front/rear bumpers, mirrors) I use RejeX.