I dunno, maybe it depends on how many in your race group and how many actually want to do it.
Say you ran 4 classes in a night and then ran this Run Whatcha Brung as the final event, the guys who don't want to do it can go home and the guys who do can have a mess around with or without the lap counter on.
Or, you could run sub groups within the one class, the fast cars up together, then the next slowest and so on.
One of the race groups I'm in were at an impasse about a new class. We ended up using Patto's 1/32 scale FJ Holden shell with either scratchbuilt plastic or any old chassis out of the spares box and what a success! Guys who hadn't done any of that sort of modelling for many years really enjoyed it so much so we started another class, same deal chassis wise but any choice of Patto's body. This has led to a third class using a Pendles plastic chassis which we got landed for about $9 each and any Patto's Aussie muscle car from 1967-80. No sticky tyres just stuff out of your spares bin, cars sliding around, similar performance what a hoot.
Sorry to ramble, just home from our 38th wedding anniversary, several beers and a couple of bottles of wine and a great meal.
Chris.