Car rental problems

I hate when I have to rent a car in a town I am not familiar with. I travel a lot and I know for a fact there is no perfect solution for parking. Add a fact that you would be driving used, unfamiliar car add to a possibility that your vacation might end up ugly. What are your thoughts on the car rental problems?

I have to admit that majority of my problems were related to the stuff that work in agencies because they were almost always unkind and impolite, to say at least. Not to mention that the car were never the quality I expected and the only answer I got from complaining was take it or leave it! Simply awful!