My beloved 2005 Prius (215 K miles) was rear-ended unto death on 20 June. I tried to get a Prius-Five (not "v" lowercase v for the Prius v wagon) with the "Advanced Technology Package", told none available in entire USA, must be special-ordered and takes 30-60 days. Wound up with a 2015 Prius-Four with the Premium Navigation confusion Package. My question(s) is(are): (a) there is a 1-inch shiny "dome" on top of the instrument panel, near the windshield, and about a foot from the right side of the car. WHAT IS IT? The dealer evaded my question; assures me it's not the Sirius satellite antenna, which they say is UNDER the car (??). I can't find the thing pictured or discussed anywhere in the manuals. (b) is there any reason I can't cover that little "dome"? (I'm doing again what I had done with the old Prius: making a matte black cardboard "thing" to cover the entire instrument panel, reaching back 22 inches in the center, to shade everything, especially the silly little screen that can't be seen when the sun is overhead).
It's the ambient light sensor. If you cover it, the dashboard will not respond by getting brighter when in full sun, or dimmer when going through a tunnel, etc.
From what else I have read, if the sensor is covered it will also affect the function of the auto headlights (if equipped, they will stay on all the time when the stalk switch is on) and the A/C system will be less "aggressive" in keeping the cabin cool during the daytime because the car thinks it's night time all the time. You could make a cutout for the sensor. I believe the Sirius XM antenna is located in the modular antenna block top rear center of the car. That explains its larger size compared to the Gen II antenna.
The Five-AT has always been tough to find. When the salesman says "none in the USA" that really means "we don't have any & I need you to buy the next most expensive model on the lot". Enjoy your Four-Nav.
On the 2010 the doohickey is only used as part of the climate control "neural network." It does nothing in regards to lighting. Don't know if that's changed in later model years or trim levels.
@RRxing Automatic headlights was added in 2012 to Four and Five trim levels. Your satellite antenna should be housed within the base of the radio antenna.
This is an old post but if you're still on the board I'd love to see a picture of your cardboard shade. I can't read the dashboard in bright light or if I wear sunglasses. i was thinking adding tinting to the windshield or creating a shade might work. Does your shade make it easier to read the dashboard in bright light?
Turning the dash brightness up to full doesn't help? IIRC, leaving one detent below full it reacts to ambient light levels, but pushed beyond that detent to the top the dash stays bright? The question marks are because I haven't messed with it in about 4 years or more, lol.