So how heavy did they said the Iveco should be?

I take it they let you drive away??

Myself and a mate are travelling in his. (I think its the same model going by pictures)

We plan in taking 3 bikes in the back.

I must get him to look at his tickets...

I found this @ http://www.steam-packet.com/en/TermsAndConditions

VEHICLE MEASUREMENT LIMITATIONS

Please ensure that your vehicle adheres to the maximum limitations detailed. If not, you may not be permitted onboard the vessel.
Ben-my-Chree: Height: 4 metres. Length Single vehicle: 12 metres. Vehicle towing trailer: 12 metres. Width 2.5 metres. Maximum Weight: 7.5 tonnes (other than coaches). The Ben-my-Chree can accommodate larger vehicles, contact must be made with the Steam Packet Freight Office on (01624) 645620 to confirm requirements prior to booking.
Manannan: Liverpool/ Belfast route restrictions - Height: 3.4 metres. Length Single Vehicle: 6.5metres. Vehicle towing trailer: 10 metres (5 metre towing vehicle and 5 metre trailer). Width: 2 metres. Weight: 4 tonnes. Manannan can accommodate larger vehicles on the Dublin and Heysham routes only, contact must be made with the Steam Packet Freight Office on +44 (0)1624 645 620 to confirm requirements prior to booking. Vehicle dimensions include any attachments which alter the size of the vehicle such as roof boxes, luggage on roof racks, antennae, aerials and bike carriers, etc.