N/P. When you get them, they should have a couple of very long wire leads on the ends, and this is to give you more choices of where to mount them. You should try to mount them onto a metal surface, like by using self-tapping screws. Avoid plastic, or trying to mount them with two-sided tape or zip ties (unless you zip tie around the wires, and not the resistor body) because they can get HOT if the flashers are on for any long amount of time.
Here's a place to look: http://jlevistreetwerks.com/store/<b>Universal-Products</b>-Exterior-Lighting/c115_116/index.html?osCsid=42330d0e2f725eb7658a8b797f4ce2ab
And to revise/rescind my earlier post, apparently there ARE "LED-compatible" flasher relays. Who knew?