ummmm
Not sure on exact measurements etc but.
Countdown - Church Corner
Cnr of Riccarton Road & Hansons Lane (access to underneath carpark off hansens lane) - I'm assuming the ground is concrete not tarseal but can't make any guarantees.
heres the 3 big malls, each has a mezzanine floor in the carpark. However, none will be well suited for a trailor, but if you are mad enough, you'll fit
A van with a roof rack can't fit in some places aparently
Riccarton Mall -
Riccarton road -
best access off Matipo st or Rotheram St
The palms
Cnr of Marshlands and new brighton rd
Northlands
cnr (ish) main north rd and langdons rd
Theres a few parking buildings in town you could try, often with first hour free parking so won't cost you anything. Not the best turning space though. All within a stones throw of Columbo st more towards the centre of town around the one way systems.