Given the Olympics basically advertised themselves as barely above amateur status a few years back and are only now starting to stretch that limitation, it will be a long, long time before the likes of F1's hundreds of millions (and I'd not be surprised if it soon became billions) dollar industry start to appear on the Olympic radar, even in a Nations Cup A1GP style competition.
Genuine single-class racing at the top end would be awesome, but the likelihood of a team releasing their drivers to compete against others in a single-tier championship with no insurance (because who would pay for it?) is below zero.
The closest we've got is the Race of Champions, and that's a glorified fun run with half world the not bothering (or scared), with talent not counting for an awful lot and entertainment at the forefront, and that's likely what we'd have if top-tier racing ever made it to the Olympics. Unless there's a massive genuine push with reputations at stake (never going to happen with any commercial rights holder or the FIA) it wouldn't be taken seriously. That's not what the Olympics are about.
Frankly the old Top Gear board has about as much credibility as the RoC, and that was held throughout the year, weather regardless, in a car which probably had it's tyres tested and that was about it.
Other than that, there's the charity kart race in Brazil near the end each year which most drivers take part in, though some miserable ********* have always refused to take part in it in fear of a good beating, even for a good cause.
We've come a long way from the 60s and 70s when drivers used to compete, seriously, in multiple series, sometimes even on the same weekend. If the Olympics didn't happen then or at any time before, it's certainly not going to happen now. Bernie and the FIA even put the blinkers on Hulkenberg (and probably others, including Alonso) racing at Le Mans again, arranging to have it coinciding with a GP for this and next year.
Anyway, if it didn't happen in Great Britain and it didn't happen in Brazil, two temples of motorsport, it's not going to happen now we're going to Asia and probably Africa for at least the next decade.
I've got more chance of competing in F1 at the age of 36 than F1 drivers have of competing in the Olympics (aside from potential oddities such as the likes of a supremely talented equivalent of a Button from a normally secluded nation in the triathlon).
The closest motorsport is getting to the Olympics is the derny or the radio-controlled cars fetching the javelins.