How are you supposed to know what events provide an appropriate challenge for your current car without loading them up and seeing the A-Spec points?

[eldomtom2]

This really annoys me about GT4 (I have not played any other GT games).

 

[forcemotorsport]

Uunfortunately there is no other way but the one you described.
You should also note that the A-Spec Pointing system is flawed, which means that for example in lower classes even low A-Spec Point rqves can be very demanding.