License plate on Dennis' SUV?

It might not mean anything. That plate number apparently just belongs to the studio.

It was used on a Ford Pinto Runabout in the "There's No Place Like Home, Part 1" episode of Lost

As for Leet

A 2 can also represent an R or a Z, or to/too/two
A 4 can also represent an A
A 5 can also represent an S

So I suppose you could get "too curious" from the plate, but it's a stretch.

It's an invalid number used on prop California license plates. The California DMV doesn't use Q, O, or I as the first or third letter of the three-letter combination. If it was a valid number, it would have been issued in 1988.