Check out this link to Mark-K web site, they tried out 10 different products over a 2 year period to see how they lasted. Very interesting as they were left out in the summer sun and winter snow to brave the elements. I'm going with the POR-15 Plucid and Helmsman combination because my truck is usually garaged if I'm not driving it. I've tried the Por-15 on Red Oak and it looks like water it that clear...
http://www.mar-k.com/wood_finish_testing_ii.html