I got this idea from the echodrivers.com forum.
I replaced the wiper stalk/switch with one from a 2004 Pontiac Vibe which is basically a Toyota Matrix. The only difference is that this has VARIABLE intermittent speeds.
Now I have 2,4,6 and 8 second delays. It's much more useful. Every fuction works except the Vibe/Matrix has a two speed rear motor that this switch does not work with. So the low speed rear wiper position does not work. But the high speed rear wiper position works like normal. Apparently you need the motor from a Vibe/Matrix to get the two rear speeds to work. Not enough incentive for me to do that.
I got the switch from a 2004 Pontiac Vibe. I chose the Vibe because ALL models came with Variable intermittent wipers and the parts guy would have a hard time screwing it up. Some of the base Matrix models came with NO variable intermittent speed switches.
I apologize for the grainy photos. There was low light and I used my camera phone. But it's VERY easy to do. It took me less than 10 minutes.
Here's the How To
1) Admire new switch
2) Remove screw underneath steering column
3) Turn steering wheel 90 degrees to the right and remove the hidden screw. Do the same on the left.
4) Pull down plastic steering column cover and then pull up on the top part. They are held in place with plastic tabs. So just give it a good tug and they'll come apart.
5) Use a small flathead screwdriver to press the tab on the wiring harness and pull down on wiring harness.
6) Use the same screwdriver to press on the front tab of the switch and the slide the switch out.
7) Slide new switch in, plug in harness and test. If it's all good, then put back the steering column together and you are done!