What dent you can and cant get away with?
With car rental you must get the dent repaired unless you have taken out the excess waiver insurance on top of the normal insurance. If you return the car with a dent on it in they will bill you for the repair, generally this is in the £250-£500 reigon !!!. Call or contact fixadent as soon as you notice it, I will be able to advise you of what you can and cannot do even if the dent repair is something I personally cannot repair by pdr I will happily give you free advice.