This video covers the installation of a 42 Draft Designs Stealth Catch Can Kit for the Mk5 2.0T FSI cars. Though done with a Stealth Can, the Ultimate Can setup can also be installed following this video guide.
The performance benefits of adding a catch can to your setup comes in the form of keeping oil from entering the combustion chamber of your motor. Inside the engine, crankcase pressure is created, which is elevated during boosting situations, and the factory vents this pressure back into the inlet piping as well as the intake manifold. Oil is picked up as this pressure vents, and thus works its way into the engine. By adding the can, we continue to properly vent this pressure however oil and condensation is trapped inside the can and collects over time. You are then able to drain this fluid at intervals to suit your needs.