there is no need to use on a 2007 car. its safe for all cars, but you will only really notice it on high mileage, older cars. even more so, on cars that have used regular gas its entire lifespan, and typically gunky oil (non-sythetic cheap-o, ie quakerstate, pennzoil (regular), or off brands). like biackromeo said, its made to break down the gunk in the engine, and make things run smoother. cars that have lifter tick issues (like G1 acura legend, as well as some others) it makes those problems disappear.

a lot of people use seafoam just before changing over to synthetic or just as a tune-up every 5 or so years. yes, in some cases it can gum up the O2 sensors and require replacement or a thorough cleaning of them, but usually it is alright.

and 1000 miles is a bit long for leaving seafoam in the engine. I would wait to do it until the day before you do your oil change. do the 1/3 1/3 1/3 method of crankcase, gas tank, pcv valve (which car on) and then run the car 50-100 miles at peak performance. make sure to replace filter after wards, as well as pcv valve.