The Game on the event ‘eligible’ cars screen only shows eligible type for the event by eligible class for the event, not everything regardless of class and also only what is default in the class - and so ignoring added tunes (only at the race entry car selection screen will you see such)… i.e. Offroad buggies B class, will not show the Ariel, Exomotive, Funco, Hot Wheels, the Polaris nor neither VW - no matter how you have them tuned in your game.
Normally it is best just to look on the map at the icon - ie. Dirt Racing, B class, Offroad buggies and go to your garage and filter for such (ignoring dirt of course, this is just to inform you of what to expect/should adjust for).
Yes, this week ‘Microcar Mayhem’ is not something you can filter for, and yes I feel the game should have some sort of glossary or otherwise inform on what is to be used when it requests this type of special type (yes you can begin to create a blueprint and pick the type and then see all cars - but many do not know this (as game does not tell you) and really you should not need to do this to find this ‘hidden’ information) - and yes, technically this is the part answering your question as to why you could not see the others on offer, but it is the beat I can offer, and it isn’t a fix for a ‘feature’ that shouldn’t be set up as it is.
TL;DR
Game only shows Type By Class, by default Factory/Game Class for the event, ignores anything outside this (not shown). - It’s a ‘feature’ working as intended.
