I use my Apex Flex as a back-up key to my car (Tesla). There’s no marking on the door pillar where the reader is and a repeater sticker will greatly help me aim for it instead of flopping my hand around the general area like I usually do (an exaggeration but that’s what it feels like). What’s the best tool to use to find out where I should place the sticker? The Test Card or the X Field Detector? Or something else? I know it should go over part of the antenna and not in the center and I could just experiment with the sticker alone but I’d like to get it right the first time.