Just a late postscript to this thread: When I informed the seller that the door handle does indeed fit a Cutlass convertible, even though the fitment guide says it only fits coupes, they replied that since I had used the part on a non-approved vehicle, the warranty would be void. Never mind the fact that the same OEM part is used for both. Fortunately, the door handle is working perfectly, and given how little I drive the car (barely over 1,000 miles in the past year), I do not anticipate another door handle failure in the near future.