Unless you are driving on a race-track conditions with speeds up to 200kph, putting spoilers on road cars like Toyotas or Hondas are purely for show. I doubt there are any public roads in the Phil. na merong straight lines and hair-pin turns, ala-Nurburgring, that you can do 200kph on a daily basis.

So there, pick a spoiler that will look nice on your Corolla and forget about the performance benefits (its negligible). I prefer subtle ones, like ducktails and low profile ones. GrupoToyota.com has Corollas in your model range that have nice spoilers. You could get your inspiration from them.