The corsa manages the 1.9 60ft due to time spent on the suspension setup and getting it to launch properly.
The 5 does it cause he bolted some slicks onto a car that otherwise couldnt launch for toffee despite being lighter than the corsa probably.
I just dont see what you find so impressive about:
fit some slicks
wind the boost up massively
run a slow time for a non road legal car.
If he goes away and gets the suspension setup properly so he can manage a 1.9 or better 60ft on road tyres and hence still run 11s in road going trim like should be possible THEN it would be impressive as a road car IMHO
Just bolting on slicks is a bodge IMHO