I remember the first (or was it second) Forum trip. There was a old Golf/jetta travelling rather quickly, belching smoke.
It lapped quicker than any of the forum cars.
Reason, the chap was local, and he knew the track. T'was only a Std 90 Hp diesel IIRC. Knowledge allowed him to carry straight speed into the corners.
The last trip Steve P lapped fairly fast in a 1.6 Suzuki swift........... Corners a plenty, if you can get round them quickly, I figure you can lap fairly quickly.
I have noticed the TTRS doth under-steer at times, but it does me.