[Stefan Bader]

But also, one car chosen by a person for the whole season would be a good idea too, otherwise people will be choosing every track the OP car for that track

There is the possibility for SRS to add restrictor % and ballast for specific car/track combos.
Although to be honest: Whilst i am MASSIVELY looking forward to the porsche cup and super trofeo races, i think the regular CP races in ACC are good enough for me and i'm not sure if i'd sign up for a regular SRS race.

edit: completely forgot: UNLESS these are multiclass porsche cup and/or super trofeo mixed with GT3 cars. Oh boy that would be great.
in case that happens: i'd put 20% (maximum) restrictor on both the porsche cup and super trofeo to keep the top speed down (would not touch the ballast otherwise the risk of people colliding during braking/cornering would increase i think)

also: even with the restrictor maxed out the top speed doesn't go down by a lot. at least on bathurst the top speed on my porsche cup test went down by maybe 5 kph

i've attached a bop.json to this post which sets the restrictor for the porsche cup to 20% on all tracks. (can be put into the "cfg" folder of a server)
@admin let me know if i should add the huracan ST to that file as well in case you decide to offer mutliclass races.

edit²: could not upload a .json file -> rename the file to "bop.json"

edit³: relevant information from the server admin handbook, regarding if a bop is already set on the entrylist (not the bop.json file):

The values of the bop.json act additive to the entry list, so you can combine a championship penalty with your track/car specific changes. Any admin command (/ballast or /restrictor) will set the corresponding value to whatever you define, and overwrite potential configurations until the car rejoins.