Check the oil. If it looks like chocolate milk or a milky latte, water has mixed with the lubricant. This causes catastrophic friction damage.
Toggle every switch. Check the heated seats, the sunroof, the infotainment screen, and the power mirrors. Flickering or delayed responses indicate corroded connectors. what to look for when buying a flooded car
Pull apart a visible wiring harness connector if possible. Look for green or white powdery corrosion on the metal pins. ⚙️ Mechanical Red Flags Check the oil