No Rivals for X class?

Finally got around to running a Hypercars championship, running an X-tuned P1. After the first two races, I noticed no Rival challenge popped up. I did the next race in a stock S2 Huayra and was offered a Rivals run against one of my friends.

Are X class cars excluded from Rivals?

Yes.

On a related note, I wish these games were relatively consistent with their car classes. In one game we have R3, R2, and R1, in another just one R, one has U, Horizon has S1 and S2… I miss E and F, and there’s cars here and in FM5 that were low enough to fit into E and F classes.

Regarding specifically the lack of X Rivals, I don’t recall looking for it, but I’d reckon there should be leaderboards for all classes that we can race. However, the only way to get X-class is via upgrades, with no car in the game being native to X. This is different from FM5, wherein the Formula One car and Indy cars were naturally X. FM4 had X leaderboards, though, and I don’t recall any of its cars being X naturally.