Hello tsikot people... i just want to share my experience in looking for a second hand car. Nag-canvass rin ako eh and medyo not good yun mga na-found out ko.
1. be careful from buy&sell dealers, hustler yan and they are very good in fixing things and making the car look really really good. Don't be deceived by how things look from the outside. (better if personal seller or referred by your friends or kakilala)
2. the transaction should be transparent... check if the seller has all documents needed. Check the deed of sale if open ba and who are the previous owners. 1st owned ba... etc. check CR and OR. you can text LTO Vehicle [plate number ex. CAR123] to see if the car record is clean.
3. if the price of the car that you're eyeing is sobra baba than the usual price of the same model elsewhere... there is always a catch so be more cautious.
4. always ask for the service record, if it's a luxury vehicle, pretty sure it was casa maintained. if the seller cannot provide it or cannot tell you which casa the car was maintained at, start to doubt na. in my experience, daming beses na muntik maloko. i've asked for the service record... the usual response i got was wala daw or sa gas station lang pinapa-service or nawala ng previous owner. when i got hold of the actual service records, the actual mileage of those cars that i asked were doubled already than what's currently on the odometer. one of the dealer who was selling me a car with tampered odometer was a trade-in dealer of this famous car brand pa. grabe talaga! (there should be a law against tampering with the mileage of 2nd hand cars here in the Philippines like in the US)
5. test drive the car and have it checked with your mechanic. list down all the issues if there are any and clear them with the seller before buying the car.

Good luck! and it's your responsibility to do due diligence.