Thank you all for the replies, much appreciated, sorry I've been busy with work and trying to find a new house. Haven't heard back from mangos just yet, but I'll phone them up tomorrow and pester them a bit.
What seems strange is that they've told me they don't know where the car is, and that it's not on their system at the moment. Though when I pressured them about the V5C, they said yeah we can see the reg on our system. Something doesn't add up, is it, or is it not on their system. I'm afraid that it might've been damaged in transit. I hope it wasn't, I hope it's just a case that it's at the port and they haven't received info of it being shipped to them yet.
Re the car being registered in 2016 and if the warranty starts in 2016. Honestly I don't care, and I really don't want to sound snobby here at all, I do apologise if I do. This will be my 5th car, and I don't plan on keeping the cars for more than 3 years anymore. I bought the current Giulietta in March 2014 (when the new facelift model came out), and I'm handing it back to FCA this month. It's cheaper (at least compared to my old Fiat Stilo) and more convenient for me to have a good reliable car that I can travel in without worrying if it's gonna break down on the motorway (I've had it so many times with the Stilo where it would give me an engine fault whilst on the motorway, had to stop get my laptop plug it in, clear errors, check it's nothing serious etc). As for part ex value, there's none in it for me, as I take a new PCP every 3 years, and just hand the other one back to the finance. So not loosing anything really if it's registered in 2016 or 2017. BTW: I'm aware it might not be the most cost-effective solution, but 1. I love having a shiny new thing :P and 2. I'm not gonna take my money into the ground with me, might as well enjoy it now whilst I can. That said I'm already looking forward to the Stelvio haha
Interesting Gaz, didn't know they do so much at the port, I thought they just unload them, store them if needed be and load them onto a lorry for transport to the dealer.
Again many thanks to you all for the replies, lots of info. You're an excellent bunch