And one final reason (if you needed it) for booking your hire car in advance is that many cars will be sold out in peak holiday periods - especially the smallest cars and the large family vehicles - so you could find yourself paying more or having to make do with an unsuitable vehicle if you're not careful.
Finally and perhaps most importantly, TravelSupermarket included a final cost saving tip, which we will let them explain: "Don't undo all of your good work by wasting money on any car hire extras such as car hire excess insurance. While this is important to buy - it protects you from excess charges of up to £2,000 if your hire car is damaged or stolen - it can cost as much as £20 a day depending on the company you have bought it through and the location. So, shop around in advance for this too. TravelSupermarket has put together some handy tips on car hire excess insurance and suggest a cheaper option. Read more here.
We couldn't have put it better ourselves.