If you want to go the Impact Wrench route but do not have an Air Compressor I have found that the Harbor Freight 12 volt Impact Wrenches (I have 4 of them) work almost as good as a pneumatic Impact Wrench.
They are made for removing the Wheel Blots or Lug Nuts and for that they also speed up Tire Rotation or will make a Tire Change quicker.
I Bought one of here newer ones about a month ago and it seems to have more pep to it than the one pictured. They sell $25-$30 depending on if there is a sale.
I also works great to snatch off the Alternator Pulley Nuts and I even manage to remove the Crankshaft Bolt on my Volvo Diesel that has more than 200 ft pounds of Torque on it.
I try to keep one in each of my Vehicles.
The Universal Joints for Sockets that have a Ball type Universal Joint are sold as Universals for Impact use.
