I really doubt mate that someone is gonna rent the personal car like this. You can check plenty of rent a car in Deira opposite arabian automobiles offering all Lexus models. Easier, no obligation and tension free than requesting from individual owner.
the starter of your car is mounted to the firewall in the center under the intake manifold. but if you have never done this before then dont initiate changing it yourself as you may damage more then you have bargained for.