You will have a ton of fun. Get it serviced often, and put it up for sale when it hits 40k miles. You won't regret it.
I've worked for a rental car company, we the employees treated the cars as bad as the customers. Things like donut contests and testing the top speed before the car was broken in were common occurrences. I owned a car that was a rental out of Hawaii and never had any issues with it. (probably just got lucky) I'd stay away from rentals but that's just me. The ford 3.5L eco-boost engine is a fine engine. I have a ford transit 350 extended wheel base high roof and the same engine makes this monster of a van move like it's nothing. I can only imagine the same engine in a car that weighs thousands of pound less. I wouldn't let the engine scare me off but I would for sure think twice about getting a high mileage rental.
Needed a laugh, this thread did not disappoint. To summarize: OP wanted opinions on a 1 year old rental car with close to 40,000 miles. Said car being a ecoboost convertible mustang. Clutchfans: DO NOT buy that car. Clutchans suggested another car on carmax for same price with only 3000 miles. OP: Bought another rental instead for more money with slightly less miles. Only two ways this will end. 1. the mustang will be wrecked soon at a car meet. 2. OP will regret his decision on buying a crappy convertible car and lose 1000s when he trades it in.
Separate topic on mustangs but anyone know of anyone whose put an Ecoboost in a classic fastback yet? I’m in love with that engine and it seems to be fairly easily put into anything you can think of such as the new GT’s.