G.R. No. L-18536 - Aznar vs. Yapdiangco

In May 1959, Teodoro Santos advertised his Ford Fairlane 500 for sale in two metropolitan newspapers.
On May 28, 1959, L. De Dios—claiming to represent his uncle Vicente Marella—called at Santos’s residence and spoke with Irineo Santos in his father’s absence.

On the morning of May 29, 1959, Irineo met Marella at 1642 Crisostomo Street, Sampaloc, Manila, where Marella agreed to buy the car for ₱14,700, payment to follow registration.
Teodoro Santos, Irineo, and De Dios then executed a deed of sale before Atty. José Padolina and registered the vehicle in Marella’s name at the Motor Vehicles Office, without Marella having paid any part of the purchase price.

Santos gave Irineo the registration papers and a copy of the deed, instructing him not to release them until full payment.
At Marella’s direction, Irineo and De Dios went to an alleged sister’s home in Azcárraga Street; there, De Dios and an unidentified companion stole the car and disappeared, leaving Irineo stranded.

Later on May 29, 1959, Marella sold the car to Jose B. Aznar for ₱15,000; Aznar paid value in good faith without notice of defect.
Upon Santos’s report, Philippine Constabulary agents under Capt. Rafael Yap-Diangco seized the vehicle during its registration in Aznar’s name.
Aznar filed a replevin complaint against Capt. Yap-Diangco; Santos intervened and claimed rightful possession.
The Court of First Instance awarded the car to Santos under Article 559 of the Civil Code; Aznar appealed.

Between original owner Teodoro Santos and good-faith purchaser Jose B. Aznar, who holds the superior right to possession of the car?
Which Civil Code provision governs: Article 559 (recovery by an owner unlawfully deprived) or Article 1506 (good-faith purchaser from a seller with voidable title)?
Whether Vicente Marella ever acquired title in the absence of delivery (tradition) under Article 712.