It's not so much that the earlier lights are smaller, but have a different angle to the lens. In 2008, Nissan made the 5.6L V8 an option and did a facelift to the nose of the R51, extending it 3-inches, which gave it more rake. The headlights, thus, were changed to match the new profile of the nose. The same headlight that was used on the 2005-2007 Pathfinders carried on a few more years on the Frontier truck. Unfortunately, neither one of them are particular good when it comes to lighting up the road, but there are more aftermarket options for the earlier style than the later style (although, may of those aren't particularly great, either). Sylvania SilverStar Ultra bulbs do a much better job than the stock bulbs, in my experience, but they are costly and do have a shorter life. A big help with the low beams is the fog lamps, which really do a good job of assisting the low beams with lighting up the road in front of you. If you don't have fog lamps, I would highly recommend adding them. There are a few that have done HID conversions with mixed results. The better conversions are very expensive, however.