BTCC rear camber

Hello all. I was watching BTCC over the weekend and noticed the majority of the FWD cars where running a lot more negative camber across the rear axle compared to the front. I'm just wondering what the reason is behind this. It seems counter intuitive as id expect this to give an understeer characteristic which id assume most drivers wouldn't want

It depends on the rear K & C and it's relationship to the front. It may be that they are treating the rear of these cars like it has a solid rear with a spool center, where you want the inside rear wheel lifting in cornering to reduce the push generated by the spool and get it to turn in.

Having more camber on the rear when rolling presents more tyre surface when it is needed, but also reduces the contact patch size in a straight line, potentially reducing drag by a small amount.