You do indeed need good predictive tools for building bridges, aircraft, spacecraft. These CAE tools are all extensively validated before they are ever used "for reals." Even if I'm using something like ADAMS, which has had people banging on the solver for years and have high confidence in it in general - I'm still going to do some verification that I've set up my models or templates correctly. Maybe a quick comparison against K&C data.
For other commercially available software that hasn't been as extensively "beat on" by professionals, I'll do a bit more thorough verification. For something done in house, I want even more extensive checks before I use it to make critical path engineering decisions. Doing this sort of combined in & out of (x-y) plane dynamics work there are potential pitfalls all over the place.
Now you do make the good point that using one data set or data point for model validation is a joke. Very easy to set model parameters to match one data point exactly - though when you use those parameters on another case your quality of correlation may be worse. Definitely requires several examples to identify model parameters which best fit over a range of conditions.
Still, I come back to the point of wanting to prove level of significance. If we drive a FSAE car around in a rock quarry - sure - your "grip" (itself a nebulous term) is probably going to suck. But for a typical FSAE event, or the one any team is looking to travel to - what's the level of significance?
I think back to running at the Ford Michigan Proving Grounds. Ride effects there are probably insignificant to handling in comparison to say compliance rates or tire setup. Could spend a day screwing with high speed dampening and ride rates and such and probably get nothing appreciable out of it - or that time would have been better spent elsewhere.
So. For any given event you're planning to hit, I think it's good to do a quick litmus test to see if it's worth investing the time in pursuing further. Effective use of time is key in this series IMO.