It would be nice to see the next update to productcart implement subcategories on the BTO page.

For instance, if a customer is configuring a computer and selecting from a range of cooling options - Stock air cooling, upgrade fan1 and then liquid cooling.

When the customer clicks 'liquid cooling' a new set of options appear that would allow him or her to select a particular waterblock, pump, etc. 

If the customer selects air cooling, these options would not appear at all.

So far, I've been able to implement this using elements from the store links switch menu along with some really ugly hacks, but for whatever odd reason if the

onClick="javascript:UpDown

command is given to either a radio button or checkbox, Internet explorer goes into a loops saying that the script is running slow.  There's some other issues as well that's just not worth the time to hassle with.

So my updated list of things PC's BTO desperately needs are:

Category icons next to each BTO category to add visual appeal

A menu that scrolls down with the updated BTO price

Multiple pages for non-conflict management BTO admins

BTO Subcategories

All of these I've been able to hack in limited support for, but they're ugly hacks and I usually end up getting asked to remove them :/