It's definitely possible. This 2001 CART race was cancelled due to concerns about driver safety because of high sustained g-forces. And that was just an open wheel racer like an Indy car.

> There was fear of the possibility that drivers could suffer "grey-outs" or lose consciousness from g-LOC. It is also likely that the high g-loads would have been outside the design limits for the HANS device, which was required for all CART races at oval tracks.

https://en.m.wikipedia.org/wiki/Firestone_Firehawk_600

The cars already produce 4-5 G when braking and in higher speed corners.

A fan car works with ground effect. F1 regulations constantly fiddle with the floor to keep ground effect in check.