Sorry to have taken so long to get back with you, but I was trying to figure out a way to accomplish this that didn't require intrusive coding.
Unfortunately, there isn't one. There is an option in the Jcarousel function that allows you to specify a starting point, but there is no way to trap which item was clicked last without customizing VM's product details page to write a server variable, and then customizing the module to read that variable and set the "start" parameter in the Jcarousel function. It would then need to destroy the server variable so that it would not be there next time the customer went to the page.
The fact that VM would have to be customized makes this change impossible for a delivered module and, therefore, beyond the scope of what we would do as support.
Jerry