Didi, Cabify, and TariTaxi are all super safe. They keep a record of the taxi number that picked you up etc so the potential for having a shady experience is pretty low since everything is recorded. Not sure what they charge non-locals, but the local rate is about 1/4 or 1/3 of the ASUR transports. The ASUR transports and Rental Cars are really designed to racket the American tourists.
Where they really get you in the rental car is the Collision, TPL, and other extra insurance they charge. They don't tell you that you only legally need collision coverage in MX which is usually included in the price of the rental. Then, instead of getting their insurance, either using a US card that provides insurance, or doubling up and buying a Mexico rental pooicy online through progressive geico etc for the VIN of the car after you rent it. For instance, we rent our car by the month here. It's $1,200 for the complete coverage w zero deductible from Enterprise. However my United card provides insurance so I don't need there's. If I REALLY wanted to cover my ass, I could buy a policy through progressive for $360 for the month that provides the same coverage as the counter rate that was $1,200.
Our cost for an SUV for a month was just over the price of USA transfers for round trip.
If anyone coming to visit would like more info, feel free to PM me.