Does mileage really matter that much for trade-in value?

Yes, mileage is one of the biggest factors. Cars driven well above the typical 12,000 to 15,000 miles a year are usually valued lower, while low-mileage cars for their age often earn a premium. Values can also drop noticeably around round-number milestones, such as 100,000 miles, because buyers perceive more risk. Condition and maintenance history still matter, so a high-mileage car with thorough service records can do better than a neglected low-mileage one.