The positive is you can access the software programs from work, home, on vacation, or even on the beach. This is a great advantage to web based systems.
The negative is also the positive in this case. Disgruntled employees can login from home and people can attempt to hack your passwords from a far.
Shouldn't you restrict remote access to just a few computers in your dealership and just a few people who work remotely? Of course the answer is YES!
Web based software can be secured by limiting the IP addresses that are authorized to login to the system. Think of it like using a firewall to guard your web available databases. Authorizing only the IP address of your dealership can ensure nobody is accessing the system from home that shouldn't be. You could then exclude certain key employees and allow them access from anywhere.
I have seen a disgruntled terminated employee log in to the dealer's inventory management system and change the prices listed on all the dealer's inventory to be below their cost. You can imagine how ugly that got.
Check with your solutions providers about securing your dealership with IP address filtering.