Some of the 2003 models came prewired for fog lights, some did not. Look underneath and see if you have the wiring in place. If not, then you will need to run Toyota fog lamps as if they were some other brand -- total cost for wiring harnesses and fogs (last time I checked) was over $1,000 ($500+ for the lights, and the wiring harnesses were out of sight!). If you have the wiring, then you'll need a new turn signal stalk and the lamps.
If you want OEM, the cheapest place may be a local junkyard that has some.
I gave up on them -- just not worth the expense required. I may one day go the junkyard route and put some in but wire to a separate circuit.
