As far as I can tell in this cryptically worded application, the request is for a patent which uses a peltier thermocouple to salvage heat energy from the car engine and then relays that electricity to a second thermocouple where the process is reversed and the cool side of the second thermocouple is used for AC.
Both these steps have occurred to car enthusiasts for decades (5 seconds on Google yielded this for using a Peltier plate engine heat to generate electricity and here and this for building a Peltier air conditioner (2003)). Wikipedia even has a page just for vehicle thermocouple generators, which have been used as far back as 1963 (Porche) as well as Nissan test vehicles. And hop on utube and you'll see lots of home-made versions of both steps. The main reason why there is less interest in the air conditioning abilities of peltier plates is that they are terribly inefficient.
I'm no expert, but I'm not sure that coupling these two processes together (generating electricity and then using the electricity) should pass the "must be useful" patent test. Both ideas have been done plenty of times and there is no value added by patenting them together. It would be like the following: Imagine that both pencils and paper have been invented but are so expensive that they are not in in widespread use, and I come along and say "I know that I can't patent paper, because someone already made that, and I know and I can't patent pencils, because someone already made that, but I'm going to patent 'the process of using a pencil to write on paper'"... and then hope that the price of pencils and paper comes down. Obviously pencils are used to write, and obviously paper is used to write on, and just because people aren't doing it today due to cost/efficiency reasons doesn't mean it's not perfectly obvious.
Also, to answer your question "How is this fundamentally different from the way other AC systems in cars are made?" - AC in cars today use a compressor (generally running directly off the rotational motion of the engine, but also possibly off of the current generated by the generator) to compress a large volume of gas into a small space. Applying the combined gas law, this means that the compressed gas is much hotter that the uncompressed gas (same amount of energy in a smaller space). This hot compressed gas is then run over a radiator (generally lots of plates of thin metal) which vent the heat into the outside air. The compressed gas is then decompressed (let into a wider pipe) but now it has much less heat energy that when it was first compressed, so it's comparatively cold. The Peltier plates, by contrast, cool via the Thermoelectric effect which causes a temperature differential to occur between two substances (generally metals) if a current was run betweeen them (one plate will heat up and the other will cool down)