AceShowbiz - "Twilight" hunk Kellan Lutz is a closet inventor, who battles insomnia with ideas for useful new products. The actor admits he lies in bed at night dreaming up items to benefit society - but invention experts aren't always convinced the Los Angeles-based star's ideas are that good.

He says, "It's something I really enjoy... It's random stuff, stuff that makes my life easier. One of the main things I started out doing was a car seat cardio... I'm always in traffic here in L.A., so I made this thing."

"I made this one prototype thing and it was the worst thing ever... My car had a headrest, so I broke it to make it, like, an ab machine... and I used to have the bands and I'd put them under my seat and I'd be curling as I'm driving... I'd have to move the steering wheel up, so I could get that full motion. I sent it in and they said, 'This is too dangerous. This will kill people'."