That is an excellent analogy. The transmatch operates much like the transmission in your car. The objective is to match the source to the load and convey as much power to getting the job done as possible. Matching the most efficient engine speed to the resistance of the road wheels involves nearly the same objective as matching the impedance of the transmitter to the impedance of the antenna. The dummy load works much like a dynamometer in simulating ideal road conditions much as the dummy load simulates an ideal antenna system. The analogy also extends to the fact that in both cases you are going nowhere, just testing. I find it useful to use the term “transmatch” to refer to a tuner located at the output of the transmitter and “antenna tuner” to refer to a network located at the feedpoint of the antenna. But, in real world language, “antenna tuner” can refer to the network placed at either end of the feedline. I use “antenna tuner” as the general term, while “transmatch “ refers to the network placed at the transmitter output. In this case it could be called an “antenna system tuner”.