From Cornwall to Ireland and back to England
 

We want to go from a week in Cornwall (down south) to Ireland for 2 weeks then back to England to continue on up to the Lake District and Scotland, then back down the East Coast to Durham where we will visit friends, finally flying home from Manchester. Our initial idea was to hire a car at the outset for the full time and to take the car on the ferry to Ireland from Fishgarth (I think that's the place) and then travel around SW Ireland, back to the port below Dublin and over to Hollyhead (again, not sure of spelling and no time to check map now).

The problem seems to be the issue with insurance while on the ferry. One travel agent tells me she can get insurance to cover the car on the ferry and another says no, the extra insurance is so that you can drive the car in Ireland but it is not covered when it is on the actual ferry! I can't seem to get a definitive answer. We checked out costs for a return ferry trip (there are four of us), including the extra insurance (according to the first TA) and it was about the same price as four flights to Dublin (one way). So, unless we left Ireland to last and flew out of Dublin, flying over and back will be more expensive than the ferry (but we have booked flights already to get the earlybirds!!). If we can't insure a hire car on the ferry then it's a no go. Has anyone done the ferry and hire car experience or have any suggestions?

Here's the answer - http://www.arrivatrainswales.co.uk/sailrail/

Don't know why you are talking about the TA being unable to arrange insurance - do what most people do and book directly with the car hire company and see what they say

You do realise BTW that flying from Exeter to Dublin will save you a day of travel.

As far as I know no car hire company will allow their vehicles to be taken on the ferries. Except some van companies that specialise in hiring vans to expats living in Spain. So do what Alan above suggests--- fly.
Use skyscanners website to find your flights and forget the Travel Agent and the charges.

I'd also fly from Exeter (or even Bristol but Exeter is closer)

I wouldn't pay to take a car across - and I also think some rental agencies won't allow it.

My In-Laws had the same issue - they ended up with two rentals - one in England/Scotland and another one in Ireland.

It is possible. We travelled from England to Ireland and back without any problems. We were 5 people and this was the better option at that stage. To fly will save time, it is true.