After multiple bad experiences renting seats (i.e. filthy seats, ripped seats, missing straps, etc.) we decided to travel with our own seats. Over 2 years we rented 9 seats and not one car rental place was able to install the seat for us - they claimed due to untrained personnel and liability as the main reasons. Bring your own seats and learn how to install them yourselves. Why not go to the police and ask them to show you how to do it? A quick check showed that every major rental company offers cars with the LATCH system meaning that once you learn to install a LATCH seat in one car you know how to do it in all LATCH-equipped cars. Good luck!