Oh dear I see your problem...is that really the original factory issse North American market rear bumper?..The MX13/23 are the same on the front as far as I am aware BUT the rear for the MX23(the very desirable coupe) are quite different..no rubber ends on them in Australia either..cannot help you but thought you should be aware..Cheers
Have a look on www.toyotacorona.com in the feature cars...my now sold (and sold again) blue MX13 is still shown in there I think..
Cheers,