I have been to a parts shop and they have a nice big bucket full of core plugs, only trouble is my old one has ripped beyond repair to size up for a new one so could i get some help from you lot as the exact sizes of this core plug:

More info would help, i assume is 1ltr engine, There are two sizes fitted 50mm and 51 mm
fiat part no.s 55182787 - £2.16 inc vat (50mm) and 91600682 - £2.75 in vat (51mm)
give dealer chassis no. they should sort for you

its a 1994 1.0L Start sorry i should have said before.
i have a local parts shop and i can size up some
they are only £1 each so i will probably buy a 50 and 51 to be sure

Need to make sure are correct type of core plug, they are not your normal type, they have a lip on to stop going in too far, most core plugs have no lip and are around 10mm depth , these have a lip and are around 5mm (if that) still not used to new money !! Unusual type of plug. May be better to spend an extra £1.50 or so and get genuine ? !
Just my advice, up to you.

hmm yeh ive ill probably give fiat a ring