3/8" ID tubing works geat to slip these in, and i found some rubber caps at Lowe's.
A little sillicone around the caps and where the wires come out, and these should be at least water resistant if not waterproof.
Links to buy these strips are in my "LED Mecca Motherload" thread... and of course I can get the parts and put some of these together for anyone who isnt Ebay-handy.
As you can see they are quite bright
I plan to try and put two in the backseat area, maybe some under the hood and maybe even "try" one behind the grille, just to see how it looks.