Where do you mount the TST 507 series Repeater?

I just talked to the TST people on Tuesday regarding this matter. I've ran the same set up with 3 campers and two truck where I have the external antenna on the top of my rear view mirror and have not had a problem except dropping reception in the rain, until I installed a dash cam! The dash cam is "dirty" when talking about Rf waves(interference). I had tapped into the fuse box and used the cigarette plug as the power and had no problem, then I decided I may want to use the camera in other vehicles and I switched to a transformer and took out the cig plug. That's when I lost all connection with the sensors. I called them and talked to them last week and they were amazed that I'd had no problem with a all 3 42ft campers and long bed trucks until now. They recommended the repeater and for me to move my external antenna to the back glass area. They advised to mount the repeater in the front compartment where the batteries are and to try and center it in the compartment if I could. With the generator shroud, it won't be a problem. They also stated that the repeater antennas needs to run front to back and not side to side. It just came in the mail today and I should get it installed next week and will let you know.