"Some minions are just full of soap, because I assume they're kind of porous and they can just spin around as the car is driving through.
"I could make a fortune."
His character Gru's idea is much less profitable.
Despicable Me 2 picks up after the events of the first film and Carell's once uber-baddie Gru is now retired and enlisting his minions to make inedible jams while he plays dad to three adopted daughters.
Nickelodeon star Miranda Cosgrove, who voices the oldest girl, Margo, said: "In the beginning Gru has totally put aside being a villain or hero and he's just a family man and dad".
And an overprotective one at that.
"Margo's a little older in this movie and Gru's freaking out because she has her first real love interest," she said. "He's every dad's nightmare, because he's only supposed to be 11 but he's super suave."
The 20-year-old said it gave her a chance to relive her teenage years and while her dad has not seen it yet, he
would probably empathise.
Carell, the father of a 12-year-old daughter, said he definitely understood, although he liked to think he would not be quite as overprotective as Gru.
"Well you certainly don't shoot a prospective suitor with a freeze ray," he said.
Instead of a freeze-ray gun, a lipstick taser is the weapon of choice for a different character in the film - Kristen Wiig's Anti-Villain League agent, who calls on Gru for help.
Carell, who also acted alongside Wiig during filming for Anchorman 2 recently, said it was obvious why the Bridesmaids star was asked to come back and play a major part after voicing a small bit in the first film.
"She's one of the supremely gifted people and a good person as well," he said.
Cosgrove, a huge fan of Wiig's, got to finally meet her during promotional work for Despicable Me 2 and was not disappointed.
"I was too embarrassed to tell her that I've seen Bridesmaids like 50 times," she said.
"She was super cool."
Movie preview
Who: Steve Carell
What: Despicable Me 2
When: Opens at cinemas tomorrow
-AAP