Rod racks probably make more sense if you are transporting salmon rods, because the joints are taped up it makes things much easier if you can leave them set up for the day. With trout rods you can simply break them down while transporting them. I now use the magnetic rod holders after a few close escapes with the vacuum holders coming loose. If you do go with the vacuum holders, make sure the surface you apply them to is spotlessly clean or the vacuum can gradually fail. I havent had any problems with the magnetic holders slipping, even on a wet surface, they can leave small scratches on the paintwork of your car if the magnetic surface and the surface of the car are not kept clean, these can easily polish out though.