The Americans were obviously crazy about the car in its time. As Mazda could not deliver enough, prices rose on the black market about the original price. The sales reached higher levels than any other rotary car. It also storied as a rotary classic after the Ro 80, despite or because it is not noticed by its design and other technology.
One accuses it to be modeled after the Porsche 924. But with a development time then of at least five years, the two years difference in appearance time probably are too short. Also, the glass in the rear divided into three parts, what has probably a positive effect on production costs.
Whether it would have fitted under the flat running front hood a conventional engine? If so, then a horizontally opposed engine or moved very farrear. But on transaxle design the RX 7 needs not to avoid. It has the compact rotary engine under the hood and Americans are crazy about it. There also the oil price crisis from 1973 can not change much. The sales numbers for the previous rotary are indeed subsided by 30%, but with the new RX 7 again rising.
In Europe the car has less chances. On the one hand, because its technique e.g. with a rigid rear axle and its performance still are not quite like the Porsche 924 and, of course, because one does not trust the engine after Ro80-disaster. In addition, the Japanese must accept import quotas and the regulate them on price. I.e. the truck is here in view of the competition too expensive. And if it would be bought nevertheless, it would be even more expensive.