2001 Mercedes-Benz M-Class ML430 AWD 4dr SUV (4.3L 8cyl 5A)
I bought this car as a Starmark certified vehicle from Mercedes. Almost immediately I noticed some issues: Two exterior plastic body pieces spontaneously broke, interior plastic parts seemed prone to breakage as well. Also, the breaks were very noisey and fluttery (dealer told me to live w/). Eventually, more serious (i.e. expensive) issues arose: fuel injectors became blocked, spark plugs fouled, coils needed replacement, power steering line ruptured... all within 21000 miles of purchase. Of the thousands of dollars in repair bills virtually nothing was covered by the Mercedes Starmark warranty. Shockingly poor quality, esp. from a company with such a premium reputation (and price tag)
Handled extremely well in snow/ice (w/snow tires). Engine had plenty of power (when it wasn't out of comission).
Build a better car, improve the recertification process, cover more items with the Starmark warranty.