For a 2006 Infiniti M, begin with the engine and driven wheels, then compare the service evidence for that configuration. A useful shortlist shows what each car was built as, what is installed now, and which questions a workshop still needs to answer.
This guide covers US-market 2006 M35 and M45 sedans. Bring the VIN, equipment records, service invoices and permission for an independent inspection. Give each candidate its own record so a desirable option on one car does not become an assumed feature of another.
Identify the five factory versions
The period Infiniti specification sheet, pages 2–3, distinguishes M35, M35 Sport, M35x AWD, M45 and M45 Sport. The M35 uses a 3.5-liter V6; the M45 uses a 4.5-liter V8. All use a five-speed automatic. The M35x is the listed all-wheel-drive version; the other four are rear-wheel drive.
On a narrow screen, scroll the table sideways. Keyboard users can focus the table region and use the arrow keys.
| Configuration or claim | What to establish | Useful evidence |
|---|---|---|
| M35 or M45 | V6 or V8; rear-wheel drive; factory equipment and later changes. | VIN-linked build information and physical inspection. |
| M35x AWD | Factory AWD identity and the condition of its additional driveline components. | Build record, drivetrain inspection and relevant service invoices. |
| M35 Sport or M45 Sport | Sport specification includes Rear Active Steer, sport suspension and 19-inch wheels. | Factory version record plus inspection of the equipment still fitted. |
| Changed wheels or suspension | Size, tire specification and replacement components currently installed. | Part numbers, installation records and fitment assessment. |
The factory sheet lists 18-inch wheels for the ordinary M35, M35x and M45. Wheels are easy to change, so use them as an inspection detail, then verify the version through documents. Keep option-package identification separate from engine and drivetrain identification.
Build a service record you can actually compare
Arrange invoices by date and mileage. For engine and cooling-system work, record the stated concern, the work performed, parts and fluids listed, and any follow-up. For transmission or driveline work, ask which assembly was serviced and whether a later inspection confirmed the result. A brief “major service” entry is a reason to request the itemized invoice.
Use the matching owner handbook and maintenance booklet to identify scheduled work. The Infiniti manuals and guides service is the starting point; request the 2006 documents from Infiniti if that year is absent from the online selector. Have the workshop reconcile gaps against this car’s mileage, age and use. Record unsupported service claims as unknown until evidence arrives.
For a Sport, explicitly include the rear-steering equipment in the inspection request. For an M35x, include the AWD driveline and installed tires. Ask the technician to identify modifications before deciding which factory instructions still apply. Use the vehicle-inspection guide to organize the appointment.
Turn symptoms into workshop questions
Write observations in reproducible terms: when the engine was first started, whether a warning stayed on, the road speed at which a vibration appeared, or whether a shift concern occurred before or after warming up. Ask for a written diagnosis, the evidence behind it and a separate estimate for agreed work. The diagnostics guide explains why a fault code is a starting point for investigation.
Request an overall inspection of body and underside condition, brakes, steering, suspension and tires as well as the chosen drivetrain. Agree which findings need attention before use, which require further diagnosis and which can be planned later. A short drive supplies observations; the workshop report supplies the assessment.
Check the VIN through NHTSA’s recall lookup and ask the manufacturer for campaign and completion records. NHTSA explains that VIN results omit completed recalls and may omit recalls more than 15 years old. Save the dated result alongside repair evidence.
Example: resolve a contradictory listing
Fictional comparison. Candidate A is advertised as an M35x Sport but has only photographs of 19-inch wheels. Candidate B is documented as an M35 Sport with service invoices. The factory list separates M35x AWD and M35 Sport. A remains unresolved until its build information and fitted drivetrain are checked; B still needs an independent condition inspection. Compare verified configurations before comparing asking prices.
If AWD is essential to your shortlist, resolve that requirement first. If either drivetrain would suit your use, compare the documented repair needs and local service support before attaching value to the trim name.
Take a configuration record to the appointment
Download the Infiniti M configuration record. Fill the factory and current-equipment columns before the workshop visit, then add findings and next actions. For the smaller sedan, use the separate Infiniti G35 guide.
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