Which car rental companies in Great Britain and Ireland will allow me to keep the same car and cross borders and use the ferry to/from Ireland either from Scotland to Belfast or England to Ireland whether to Dublin or Rosslare or even Holyhead to Dublin????
You are free to cross borders with rental cars.
The only thing you'll encounter are huge charges if you pick up the car in one country and return it in another.
what do you mean by huge fees? hundreds of dollars?
Hundreds of pounds more like.
Also be sure the insurance covers taking car on ferries to be sure it is covered. I very well could be wrong but doesn't hurt to check.
I'm just got off the phone right now with the car rental agent who is a pleasure!! i won't have to pay any extra "fees" to cross from scotland to england to wales. if i take the car to ireland or to france or anywhere else in europe, i will have to pay a 30 pound per day break down fee is what it is. I highly recommend rentalcars.com. we used them this summer in california.
Remember England, Wales and Scotland are all part of the same country with the same licence plates, and same insurance laws. You are not crossing an international border on Great Britain. Ireland is different, Northern Ireland and the Republic of Ireland are different countries and you may have difficulty returning a UK (NI) car in the Republic and vice versa.
So, glad to see MC chiming in here. The Better Together's won in Scotland, so we don't need to worry about the drop off fees for a bit longer! :)
And, from personal experience, it really is not that hard to get two cars in one trip. :)
Pam
Ireland also operates under different rental car insurance rules than just about anywhere else. This is the place where you want to/are required to pay for the CDW offered by the rental agency because only a handful of credit card insurance policies are valid in Ireland.