Not knowing how old your existing unit is,it may be better to buy a new satnav that comes with uk and western Europe maps as standard.I would recommend the tom tom 5 inch screen,its on amazon at £74.99 was £129.99 as per moneysavingexpert.That tom tom satnav advance lane guidance which is excellent,tells you what lane to be in in advance,very useful.Good luck with your travels.
Harry Jay ● 3679d