My IS300 came with an antiquated navigation system that wasn’t working. My research indicated the DVD player under the trunk platform was at fault (map updates are provided as DVDs from Toyota/Lexus for a fee). A used replacement DVD player would be a few hundred dollars ($6000 new from Lexus lol), and I suspected the software would be substandard if I ever did get it working. So instead, I decided to gut the unit and install a standalone GPS in its place, retaining the neat hinge feature that stows the screen away when the vehicle ignition turns off.
I had seen a few users on the my.is forum pull off this install with older third-party GPS units, but none that were on the market when I bought mine. I chose the Garmin DriveSmart 61 after comparing its measurements to the housing internals and crossing my fingers it would fit.
This housing assembly was incredibly complex for how simple it appeared from the outside. I had to carefully handle ribbon connectors, anti-vibration foam, tiny screws, and parts captured by wire routing. The factory service manual contained no instructions or parts breakdowns. The only hints I found were on the electronic parts catalog on ToyoDIY.com.
I secured the new self-contained Garmin unit inside the frame of the old display by shimming the inside of the frame with steel tabs and a few other implements. This secured the screen up and down and side to side.
I then had to clamp the front plane of the unit against the frame’s bezel. I used cable ties to create tension between the sides of the frame. Since the holes attaching the cable ties were farther forward than the rear surface of the GPS unit, the cable-tie tension created forward pressure on the unit. I added some adhesive foam pads to create flexibility in the interface and to “bulge” out the cable-tie band more, orienting more of the tension fore/aft.
I then installed the whole assembly back in the car and used the new GPS unit for a bit without the back cover to ensure everything worked right.
The next step was to get rid of the externally-routed USB charging cable to the 12V outlet, and route the charging cable behind the dash and over to the driver’s side kick panel. There I used an “add-a-fuse” kit to provide the GPS keyed and fused power. It automatically turns on and off when 12V power is applied or removed.
It retains the automatic raise and lower action when the ignition is turned on/off.