2003–2004 Infiniti M45 Ownership Guide
Garage Guide Verdict
🟢 Highly Recommended
The first-generation Infiniti M45 may be one of the most overlooked V8 luxury sedans ever sold in North America.
Powered by Nissan’s legendary VK45DE V8 and riding on a rear-wheel-drive platform, the M45 delivered effortless performance, luxury accommodations, and distinctive styling in a market dominated by German competitors. While sales numbers were modest, the M45 has earned a loyal following among enthusiasts who appreciate naturally aspirated V8 power, Japanese reliability, and sleeper status.
Today, the M45 remains one of the best luxury performance bargains available.
Garage Guide Ownership Score
🟢 9.0 / 10
💎 Garage Guide Sleeper Series
“The Forgotten Flagship.”
Reliability Snapshot
🟢 Reliability: Very Good
🟢 Maintenance Cost: Moderate
🟢 Performance: Very Good
🟡 Modification Potential: Moderate
🟢 Daily Driver Suitability: Excellent
🟢 Long-Term Ownership: Excellent
Buying Checklist
Vehicle History
✅ Verify clean title
✅ Review maintenance records
✅ Confirm mileage history
✅ Verify ownership records
✅ Review accident history
Mechanical Inspection
✅ Verify VK45DE operation
✅ Check transmission shifting quality
✅ Inspect cooling system
✅ Verify oil change history
✅ Scan for diagnostic trouble codes
Suspension & Steering
✅ Inspect front suspension bushings
✅ Check steering rack condition
✅ Verify wheel bearing health
✅ Review tire wear patterns
Interior & Electronics
✅ Verify climate control operation
✅ Test power seats
✅ Inspect Bose audio system
✅ Check navigation system (if equipped)
✅ Verify all electronic functions
Garage Guide Tip
A well-maintained M45 can easily exceed 250,000 miles.
Service history matters more than mileage.
Best Model Years
🥇 2004 M45
• Final production year
• Most refined ownership experience
• Strong enthusiast demand
• Best long-term value
🥈 2003 M45
• Launch year
• Excellent value
• Increasing collector interest
Garage Guide Note
Because production was limited, condition matters significantly more than model year.
Proceed Carefully
Oil Consumption
Monitor oil level regularly and review service history.
Cooling System
Inspect radiator and cooling components carefully.
Suspension Wear
High-mileage examples may require suspension refreshes.
Interior Electronics
Verify all electronics function properly before purchase.
Garage Guide Warning
Clean M45s are becoming increasingly difficult to find.
Mileage Expectations
Under 100,000 Miles
🟢 Exceptional
100,000–175,000 Miles
🟢 Excellent
175,000–250,000 Miles
🟢 Common
250,000+ Miles
🟢 Very Possible
Garage Guide Tip
Properly maintained VK45DE engines routinely exceed 250,000 miles.
Ownership Budget
Estimated Annual Ownership Cost
🟢 $1,000–$5,000+
Depending on mileage, maintenance history, and ownership goals.
Vehicle Highlights
🏁 4.5L VK45DE V8
🏁 340 Horsepower
🏁 Rear-Wheel Drive
🏁 Luxury Interior
🏁 Bose Premium Audio
🏁 Strong Reliability
🏁 Excellent Highway Cruiser
🏁 Sleeper Performance
🏁 Rare Production Numbers
🏁 Future Collector Potential
Ownership Score Summary
Pros
✅ Strong V8 performance
✅ Comfortable highway cruiser
✅ Excellent reliability
✅ Unique styling
✅ Affordable ownership
✅ Rare and distinctive
✅ Sleeper status
Cons
❌ Fuel economy
❌ Limited aftermarket support
❌ Aging electronics
❌ Finding clean examples
Garage Guide Final Verdict
The Infiniti M45 quietly carried the torch for Nissan’s luxury performance heritage after the Q45. It delivered V8 power, rear-wheel-drive balance, and luxury comfort without demanding attention. While it never achieved the recognition of its German rivals, the M45 earned respect from those who understood what it offered.
The M45 wasn’t built to impress the crowd.
It was built for the driver.
Garage Guide Ownership Score
🟢 9.0 / 10
Garage Guide Verdict
🟢 Highly Recommended
💎 Garage Guide Sleeper Series
“The Forgotten Flagship.”
🏁 Build Smarter. Drive Longer.™