Check the cable, it gets broken especially in the places where you can see it or at its movable parts.
Do I need rubber like caps on new replaced bulbs in the dash
check the wire loom next to the trunk latch, open it up and check for broken wires. Common problem from flexing
Camry 1999 has only on bulb for both low and high beams.
Check both bulbs, they run off of the same fuse as the tail lights,
have you checked the bulbs and fuses
3157
Rear license plate lights replacement require that you remove the entire frame with reverse lights. Remove the 3 cover bolts on the inside of trunk, remove license plate, remove the for bolts holding frame to tyrunk lid, slide unit down and out and you will have to twist the bulb sockets and remove the bulbs and install in reverse.
take out the bulbs and see if they are burned out.
Check the fuses first then check the bulbs.
It is one big peice that must be removed. If you open the trunk, look on the inside of the lid behind the license plate, and you will find a few nuts that once removed, will allow you to remove the entire rear facia panel that the license plate bolts to and which houses the "PONTIAC" lights.
check the switch at the break peddle
If you are afraid of breaking something take it to a garage.