Alternatively, when I called AutoZone the employee I spoke with said they use a Midtronics tester with a built-in printer, though he didn't know exactly what model. Sounds at least similar to the MCR 717. Would having a free test run by them with a printout or cellphone snapshot suffice for warranty coverage?

I tried looking for a MCR 717 and it doesn't seem readily available for purchase.

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280