Thanks for the report, after testing it myself with another player, we were unable to come up with the crash after driving around in the truck for a solid 10 minutes while getting in and out of it.
This could be an issue with your cache files for the server. I would suggest you do the following to see if the error continues to happen:
Open the FiveM Application Data folder
Delete the "caches.xml" file
Then, go into the "cache" folder
Delete the "priv" folder
Delete the "servers" folder
Then hop in-game and try the vehicle again
If you do not see the FiveM Application Data folder, RIGHT CLICK FiveM.exe and click "Open File Location" and continue with the provided steps.