Hi,
we say about configure settings. If you update component - we save your settings.
But if you changed CSS or HTML or PHP, If you changed same layouts - you lost them.
Our
car rental dealer software Open source - so you may change there all.
But, When you do update - we recommend for everybody: do backup first - with this you not lost something important!
When you do change for some Joomla code we recommend:
1. if you need change layout, please copy current layout, to other name - and change it.
In OrdaSoft
car rental dealer software - you may select layout for show.
2. When you add CSS change, best if you create some custom.css file - and all changes add to it, so in case any update - all changes you will see in 1 file
3. Please do site backup 2 times per month, if the more often - better! so any Update on hackers will not scary for you
Regards
OrdaSoft team