I am having my done next week. Line X Extra. By my research you need to go under the rails. I am assuming you are talking about the tracks for the adjustable cleats to tie down stuff in the bed. This Line X dealer is accustomed to taking them off including the bed bolts, tied down cleats, and tailgate bolts prior to spraying the bed. I did talk to my Toyota dealer and it's acceptable to take them off and put them back on.

 

I had over on my last truck. But it did not come with built in protection from the factory.

The 07 Tundra already has over the rail protection, so no reason to spray it.

 

For me it's an easy decision. If the bed comes with rail caps then under, if not, then over. I always want some sort of protection for the tops of the rails.

 

When talking to the linex in anaheim california, "over/under the rails" was explained to me as having nothing to do with the deck rail system; instead, its the top of the sides of the bed. In other words,if you were on standing next to your truck, and rested your arms on the sides of the bed (so your arms are parallel to the ground), the portion of the bed that your arms are resting on is the "rails". I hope this makes sense; I'm getting a headache trying to correctly describe what I'm picturing in my head...

So, if your use of the truck includes scenarios where you're abusing these rails, then going over the rails would probably be a good idea.

Hope this helps...

 

My Line-X dealer in Atlanta went under the rails around the three sides with rail caps and over the rail at the front of the bed under your rear window. They explained to me that is standard when there are rail caps installed. I had the Xtra done, it looks great and I have no issues with the operation of the tailgate.

 

Yikes, this shouldn't be so confusing but I 've seen it several times. I make a motion that from this point forward we refer to Toyota's moveable cleat tie down system as the "Bed Rail System" - which is what they call it. The actual truck bed rails are the top most horizontal section of the truck bed that's covered with black plastic caps. Click your heels together 3 times and say "Bed Rail System" ....

 

AH.. thanks for this post.. Clears things up for me.. I also thought the lady at Line-X local dealer was talking about the bed rail system!