1. Where can I find most translations? 

-Car Rental -> Translations

2. What can I do here? 

-Add a new language and translate the website

-Modify any existing text on the website: ie. You can change "VAT" -> "Sales Tax" 

-Yes, you can translate English text as well!

-Manage your Terms and Conditions in every language 

-Manage your various e-mail text in every language

3. What if I am not using an Ecalypse theme?

You need to go to Ecalypse rental -> settings -> and set "Are you using an Ecalypse theme?" to no.