If you have new tires (less than a couple of months), the compound that is used to help release the tires from the molds tends to prevent products like tire wet from adhering to the rubber. Thus, it gets slung as you drive = streaks.
Just spraying it on results in a lot of excess on the tires. I find that applying with a sponge works best. It goes only were I want it to go: not on wheels or body paint (if you have a plastic bumper). And I use less, too!
I'd add only that, to a point, the longer I let the car stand before driving, the longer the application seems to last. I try not to drive it for at least 3-4 hours. When I can, I do the rubber detailing on one car at at time. That way I can park the detailed car overnight and drive the other car. Instead of looking good for just a couple of days, everything stays nice and black for a week (although brake dust does take its toll).