The scenario you present is interesting because it presents an important nuance.

By "third party liability" I assume you mean what is commonly referred to as the rights which may belong to a "third party beneficiary" to a contract.

Generally a third party will have the right to enforce a contract against a non-performer, in which they are to obtain a benefit when they gave no consideration to the non-performer, when the contract is explicit that the contract is being made for the benefit of the third party as part of the consideration.

I think that your facts are slim on showing that Sally has a right to obtain the vehicle based on the contract presented. There is no explicit representation from Mike to Ace Autos that the car is being bought for the BENEFIT of Sally. Rather, the contract described makes the delivery to Sally a condition of the contract - you could easily substitute "deliver the car to my office address" and it would still be a location. There is no explicit statement that the car is being bought "for Sally."

Additional facts may indicate that Mike's intention were communicated to Ace Autos, but this may require the showing of parole evidence which may not be admissible.