It's an uneasy feeling all parents eventually face: handing the car keys over to a teenage driver.A San Diego native's new invention aims to reduce those fears, but some question the real cost.The product will hit the market in two weeks.Some call it a big opportunity to cut down on teen accidents.Others say it's too much "Big Brother."New graduate, Carleen Anderson, just got her high school diploma.I don't have to have rides anymore, Anderson said.She also got her driver's license. A dream for a teen. More worries for a mother.You send up a prayer. You just pray to God they're going to be safe, said Carleens mother, Lena Anderson.Safety concerns are nothing new for parents when it comes to teen drivers.Crashes remain the number one killer of young adults.A reality one new product is aiming to change.Enter TIWI, a new onboard computer for vehicles created by San Diego native, Scott McClellan.Mounted in a teen's car, it sounds an alert in the vehicle and informs parents when their child is not driving safely.Parents can also get real-time e-mails and text messages about the teen's driving.Parents can also be notified when their child has arrived at school or if the teen is going to places he or she shouldn't.TIWI can even alert parents when a teen isn't wearing a seat belt.With years of testing, we've demonstrated a 90 percent reduction rate of accidents in our customers, company officials claim.It may be a boon for safety but some teens are calling it a permanent babysitter, one that may go too far.It feels like they're on your shoulder, always watching. I get enough of that at home. I don't want to be tracked as well, complained teenage driver, Sam Kirkendall.What the teens call tracking, the company calls mentoring.Whatever it's called, some parents say they'll use it.I'd just feel much safer, said one.Absolutely, that gives me peace of mind, said another.But that peace of mind isn't cheap.The computer costs $450 with additional monthly subscription fees ranging between $20 and $30.