Fuel injection directly into the cylinders was first indroduced by Mitsubishi, this is a couple of years ago. I know that Volvo also used that Mitsubishi engine, but it must have been at least five years ago that engine was introduced, and even earlier in Mitsubishi cars.
Audi is also using direct injection in their LeMans racer since it gives a better fuel economy. But if we look at an F1 engine they have the injectors placed in the plenum, one for each intake since that gives the best air-fuel blending.
Ferrari F1 engine:
http://www.alfapower.nu/albums/album58/acq.jpg
http://www.alfapower.nu/albums/album58/abx.jpg
Audi LeMans engine:
http://www.mulsannescorner.com/Audi-SP2.jpg