I've seen plenty of barry cars but its rare I see a badly riced out VW, let alone a Polo like that. Polo modders (and generally lupo, golf) seem to be a fairly sensible and sympathetic lot, if those are the right words to use. Well you know what i mean.... they're not a big load of childish tosspots with frontal lobe damage
(heck i'm still not entirely sure the MG round the corner is barried - just not all that well done. it hasn't got a bodykit, spoiler, or huge zorst after all
Insurance, maybe servicing costs are the only things I can think of, other than a particularly rabid pack mentality that means its a Nova or nothing (casts wary eye up and down messageboard

... hmm).
Basically:
Nova and the type of Corsa that chavs go for - insurance group 1, maybe 2 if they have ideas above their station, and parts that scrappies almost pay you to take away (none too expensive new either). Saxo, free insurance for a year on the right ones, dunno after that. Parts probably not so bad as there'll be enough of them being written off right/left/centre/surround/subwoofer.
Polo: insurance groups 4 and 6 for the 1.0, 1.3 (and GT? or is that 7,8? G40 is insane

). Not the highest, sure, but enough of a hike over group 1 to scare the kevs away. (Heck, even I set myself a limit of group 6 when looking for a car - it gets iffy kinda fast past there). Parts cost doesn't exactly strike me as being bargain basement, but I can afford it.
I have a job after all, even though it IS part time

Being on the dole AND spending a fortune on bootleg fags and white thunder* kinda eats into your funds after all.
(*white lightning is too expensive)
Purchase cost probably comes into it as well. You can get a running, though maybe free of MOT/tax (what do they care..) Nova for the cost of a new pair of prison-white trainers. Polos still start at around £250... no matter how old they are
Given all that though, I'm not sure why to date I've only seen one modified Fiat Panda (and it was a damn good one, too). ALL of them are group 2 insurance, the 1-litre engine is comparitively "hot" in such a lightweight tinfoil frame (even compared to a Nova) and built like a brick outhouse so you can boost the heck out of it (can't chip it though, as its a carb - mebbe that puts them off

), its got Italian sorted handling, and parts.... well pshh.... walk right into the yard and take them away, even the owner's dog won't stop you.
Or perhaps its the availability of bodykits and other chavvie mods? Go down halfords and have a browse (like I did, wondering about the possibility and price of wheels, induction, zorst from there... once). You'll see a bucketload for all the typical rice cars.... can you get anything for a Mk2/Mk3 Polo (or a panda

)??? Can you hell.
Annoyed me a little at the time, but it was a blessing really. Plus their prices suck.
(I did not look at the body kits, or the wings, and I did not have sexual relations with that woman monica lewinsky neither)