[Bruce Robles]

Sounds a little excessive, 5 laps at Willow in October to heat the tires? 10 laps to figure who's the best?
If the driver, or drivers really know the track and have driven there in timed events so they know how to put together good laps, and as already been metioned he must be consistant, he or she should get your results in 5 laps max.
But you want to find the best "Handling" car not the fastest car. So a Slolom would be a better format than Willow's long sweeping banked road course. Are you planning to clock corners times at all the corners and measure g forces?
By the way:
Could some one tell me why you'd want or even need a overdrive 5th. at Willow with a 3.55 rear end unless your running go-kart wheels? Seems to me that you spend more time going up and down the gears, than your taking seconds off the clock.
In 1972, with the Trans Am Championship winning AMC Javelins, the cars weighed 3200lb. and we ran 4:30's with a 4sp. and George Follmer ran 1:28's in testing.
My brother and I ran our GT-350R there in the '60's with 3:89's and eventually we went down to a 4:11 and it was faster. Went from low 1:37's to low 1:36's just like that! It's still about how long it takes to get from A to B, not how fast your going when you get there.