does anyone know if local councils in the UK follow up on parking
tickets they give to foreign number plate registered cars?

I would doubt it because how could they enforce it if the car is
outside the jurisdication of the courts?

This, from a December 1999 Select Committee on Environment, Transport
and Regional Affairs meeting would seem to indicate that the answer,
three years ago, was NO - unless the vehicles are clamped or removed,
in which case the driver is likely to pay up to recalim the vehicle.

I don't have any more up to date information, so cannot post this as
an answer- unless you are happy that nothing has changed in the last
four years.  Perhaps another researcher will be able to confirm the
position, one way or another.

"438.  That would apply to foreign vehicles as well as UK vehicles?
  (Mr Lester)  That would apply to any vehicles. Currently it is an
unfortunate feature that foreign registered vehicles may in certain
circumstances be more likely to be clamped or removed because it is
the only way of enforcing the penalty. It is unfortunate. It is not
something we would like to have. If we had access to the vehicle
keeper databases in, say, France and Belgium, Holland and Germany,
which are the main visitors to London, so that we could enforce the
debts through those keepers then that would not be so likely to
happen."

Source: http://www.parliament.the-stationery-office.co.uk/pa/cm199899/cmselect/cmenvtra/32/8120917.htm

Search strategy: Google
Keywords: foreign cars "parking tickets"
foreign cars "parking penalties"

Best, r2l

Judgments obtained in a UK jurisdiction can usually be enforced in
other countries - in EU countries this is done in a prescribed method
according to the Brussels Convention.

However, it simply isn't worth doing this for the (relatively) small
amounts involved in parking tickets. That's why, as read2live-ga
helpfully points out, is why a foreign registered car is more likely
to be clamped or towed.

This has especially had an effect with the London Congestion Charging
- foreign registered cars simply don't have to pay it.

If European federalisation (dirty word ;-) continues, then eventually
the mechanisms will exist so that parking fines can be enforced across
the whole EU.

Silly me, I did of course mean the Brussels Regulations, not the Convention.