Have 2015 4 Runner....During summer of 2017 a squeak in the front end developed.
I tried everything, dealer, WD40 everywhere.....but not in the correct place. Happen to find the problem by pure luck....
I'd tried pushing down on the front end, more than a few times, to try and get the squeak to be heard.....no could do.
Happen to drive to a friends house, when I got out, grabber the "upper part of the opened door and pushed down......sound was there.....did it a few more times, sound continued......had friend come out and listen, did the door bit, sound was there....he asked me to open hood..NO SOUND CAME WHEN I PUSH DOWN ON OPENED DOOR.....got some grease put on hinge, closed hood....push down on corner of door....PROBLEM SOLVED