Yesterday I hauled some large boxes in the trunk and had to tie the trunk lid down as I couldn't close it. The entire ride home I had the flashing warning light and annoying beeper. Luckily, I only had to go two miles. Is there a way to silence the warning? Surely, I'm not the only person who had to tie down the trunk lid while transporting large objects.

 

Yes, you can close the latch of the trunk with a screwdriver.

 

That's probably the best way to cut off the beeping for a short time. I've tried to silence several beeps in several Lexus cars, and it's pretty hard (although the RX speaker wire on the hatch can be unplugged, as I recall). Fabricating a device to push the switch into thinking the trunk is closed should work. If the screwdriver seems a little on the brute force side, and if you see a need to do this from time to time in the future, it would probably be worth your while to fashion a piece of wood or plastic (or pvc pipe) to insert and remove quickly. Maybe somebody can use one of those 3-D printer things to produce something that would do this. Maybe others here would be glad to buy it to keep in the trunk.
I'll take a look at the latch when I get to my car and see if inspiration strikes.