I much prefer the magnetic mount that fits on the air vents. I use it on my IS300 and it fits perfectly and doesn't wobble or get in the way. I used the night ize steelie mount setup and I'm happy with it.
2004 IS300 8N6 automatic - F&F Coilovers, Eibach sway bars, DIY Intake hardpipe, FR-S LSD swap, buddy club driver seat, Aftermarket HID's and LED Tail lights, Trunk strut mod
.....Soon to be NA-T with CX Racing hard parts, Garrett 60-1 turbo, Tial 50mm BOV, Tial MVR wastegate and FIC 6 piggyback