Open Lexus Trunk - Battery Dead

1. If the car battery is drained, the only way to open the trunk is by gaining access to the car with the manual key. 
2. Press the release on the keyfob and remove the vehicle's manual key. 
3. First, check for a  keyhole in the trunk and use the key to unlock the trunk. If there is no keyhole in the trunk, you should see a keyhole in the driver's door.  The cover should come off without much effort and will cause the hidden keyhole to be revealed.
4.  Put your key into the keyhole and turn it to unlock the driver's door. 
5. Your car should open. 
6. Now that you have opened the car, press the trunk release button. If the trunk is electronically operated, it won't unlock if the battery is dead. Pull the hood release and open the hood. 
7. Connect a jump box to the jump-starting terminals. Connect the positive (red) clamp to the positive terminal. 
8. Connect the negative (black) clamp to an unpainted bolt on the frame. Do not connect directly to the negative battery terminal. 
9. Now that the vehicle is powered up insert the key in the ignition and turn it on. 
10. Press the trunk release button. 

When the car battery dies on a Lexus, you won't unlock the button by pressing the trunk release button on the key fob. 

Use these instructions to unlock the driver's door and open the trunk manually. If your Lexus has an electronic trunk release, you will need a jump box to power up the vehicle.