In my home town in Baguio City, usually two short honks means "Thank You". Example, pinag-bigyan mo makapasok 'yung taxi (or any vehicle), two short honks ang sagot nila. So I do the same, kung pinag-bigyan ako, I'll honk two short times.
But here in Metro Manila, none.

xD Kahit mga kapit bahay mo sa subdivision, pag-bigyan mo, nothing. It seems "thank you" is a non-existent gesture here. Anyhow, I honk two short times kahit saan ako mapunta kung pinag-bigyan ako.
Depende na siguro kung saang kultura ka lumaki.