I've just been trawling the web for a good price & whilst going through the motions of filling the form in I stopped by the "have you any mods?" section.
For the heck of it I ticked the yes box & up popped a screen with a list of stuff including towbar, reversing sensors, sunroof, alloys, tints ...
On another site I did the same thing - no mention of half the stuff listed on the first site.
I would urge everybody to tick the 'yes' box just to see what they call 'mods', you can always come out of the mods screen and tick no instead - better that than find out you're not insured after a crash!