If you don't wish to use ASI mods, then this CLEO will help you to open car trunk on very simple way. Just press TAB and trunk will open with unique sound effect. While you driving, trunk will move and if you drive too fast, trunk will close by itself (similar to doors). Unlike ASI mod where trunk will be open with door sound effect and stay static even while you are driving.
Enjoy and please subscribe to my YouTube channel:

https://www.youtube.com/c/Dragomazing