Gr. 4 is pointless in Sport Mode, especially now that we have three other groups which are better with the introduction of Gr. 2. Whilst being a perfectly enjoyable group of cars, Gr. 4 is little other than an inferior version of Gr. 3. The only thing it offers which Gr. 3 doesn't is some unique cars and different drivetrains (e.g. the Gr. 4 GT-R is 4WD whereas its Gr. 3 counterpart is FR), but this does not make it worthy of a slot in the very-limited selection of daily races. Now that we have groups 1-3, all of which are faster and therefore more fun than Gr. 4, this group serves little to no purpose to the game, and it should feature a lot less than it does in Sport Mode, if at all.
There may be a bigger issue here, as PD continue to limit us to three daily races per day, with many of us complaining on a regular basis that a given day's selection does not suit our personal taste. Either way, I feel that Gr. 4 only gets in the way of having much more fun races in the form of Gr. 1 and the newly-introduced Gr. 2. Discuss if you so please!
The data has disproved the hypothesis