cooling uing car rad core

i hear u can use radiator cioils or cores from cars for a radiator, ok then if neone has used one what car is it best to get one from eg size of coil! (uk cars only plz)

i think you mean the heater core, and the most popular ones around here are the Chevette adn Caprice core both from Chevrolet cars, i'd like to think that chevys have made it across the drink to you, but maybe not, so then i'd say go to the local auto parts store, and ask to look at some heatercores, then pick out the one you want
here they are like 15-30 dollars

however if you mean a real live radiator like the one in front of the engine, then good luck those are like 150-200 dollars a pop

Heater cores are the most commonly used computer water cooling "radiators."
In fact, many of the popular commercially available pc radiators are just pre-modded (barbs of the correct size installed) Chevy Chevette heater cores.
(A heater core is the small radiator inside the dashboard that actually heats up the interior of the car, to clarify.)

Heater cores from just about any vehicle will do though, and be less expensive.
What you want is a core that will:
fit fairly easily in your case
be easy to mount fans on
be preferably made of copper
have two "tanks" separated by finned tubes
have inlet/outlets that are the right size or bigger (to make it easy to use and/or mod.)

Chevy Chevette cores are popular because of the copper construction, being sized well for 120mm fans and have nice big inlet/outlets.
And they are cheap (in the US anyway!)

Personally, I also use a Chrysler heater core in one of my machines, and have seen computers with Toyota, Nissan, Ford cores to name just a few.

If you can't find a suitable heater core locally, then you may be best off with one of the commercial cores- DTek and DangerDen both have Chevette-based units I believe, and there may be other suitable ones closer to you.