The COT will be phased into competition with 16 races next season, including the October race at Talladega, and NASCAR used the test to help develop proper specifications for that event.

``NASCAR wants to make sure they get the right restrictor plate and gear ratio for the teams,'' Jimmie Johnson said. ``I think that is one of our main goals in the test.''

NASCAR used a variety of different restrictor plates during the test, beginning with one that had holes of 15/16ths of an inch in diameter _ or 1/16th bigger than what was used in Sunday's Nextel Cup race.

``We actually were doing a whole matrix of plate changes, but we also know there's a lot that sits under the plates that dictates speeds,'' series director John Darby said.

Darby said the COT will not eliminate restrictor plates, which NASCAR uses at Talladega and Daytona to sap horsepower and keep the speeds under 200 mph.

``The concept is eliminating specialized restrictor plate engines,'' Darby said. ``I don't think the elimination of the plate is possible, but we can eliminate the specialization.''

At least two of the 13 drivers testing weren't overly enthusiastic about the extra work, or the prototype itself.

``It's been like watching paint dry,'' Greg Biffle said. ``It's costing us a tremendous amount of time and money to do this, when we could be working on getting ready for (Saturday's race) Charlotte. But if you want to play this sport, this is what you have to do.''

The biggest complaint was speed. Since the plate/gear combo has yet to be determined, the cars are slower than what the drivers are used to.

``We were a good five miles slower per lap than what we ran in Sunday's race,'' said Jamie McMurray, referring to average race speeds that eclipsed 200 miles per hour. ``And I didn't feel like the cars drove better. You still get loose when guys get in your rear quarter-panel.

``Really, I think this test is more for NASCAR than for us.''

The Car of Tomorrow has been a five-year project aimed at improved safety, performance, competition, and cost efficiency. It is scheduled to run 26 events in 2008, and be used at all NASCAR events in 2009.