either way I'd check with insurance and get a quote reference number and see how long the quote lasts for.
else when the time comes they may just say feck off
I know its a more sensible car, but if there are more than just a few basic mods they will fob you off. with a higher car you *may* be able to get insurance, albeit at stupid money.
I take it you are gonna fit the abarth kit to another set of bumpers, then do what you will. try and get it colour match (would not be easy IMO) at a good paint shop?)
then if it all goes pair shaped on t'insurance, just whack the OE bumpers back on (as theywill still be std and servicable?).
thats what I would do