I have installed on my website your theme with Car Rental Booking System for WordPress plugin. I have had no issues until a few weeks ago when, after updating your theme to the last version, it has problems to run. My website is bewinkle.com/alquiler and, as you can see there, our clients cannot make any booking as they cannot select on any dropdown.
They say that the problem is the theme for that .js. I dont know exactly how has the problem because I am not developer, but I need to make the dropdown works. You could try on our website https://bewinkle.com/alquiler-para-revisar/ that they are not working properly.