Did not get this to work any way I tried to modify the flypage.tpl.php file. If I got the 'Customer Reviews' to disappear, the other tabs stopped working; clicking on one of them made all black and it was impossible to go back to e.g. 'Related Products' the tab just remained black and did not show any information anymore.
Instead I added the following code at the very bottom of the s5_tabshow.js file (>components>com_virtuemart>themes>default>templates>product_details>s5_tabshow.js):
document.getElementById("tab_s5_a_ts_tab2").style.display = "none";
... so it would look like this:
var s5_tab5_length = document.getElementById("tab_s5_div_ts5").innerHTML;
if(s5_tab5_length.length <= 30) {
document.getElementById("tab_s5_a_ts_tab5").style.display = "none";
}
document.getElementById("tab_s5_a_ts_tab2").style.display = "none";
This removed the 'Customer Reviews' tab.
BUT, it would have been better to link it to the parameter 'Enable Customer Review/Rating System' in the global config of VirtueMart. I could not find how to do this, should be quite easy I think, as the other tabs are content dependent.
Any suggestions?