I believe (may be mistaken) MOST of the vendors re-sell the same supplier product, because it looks (to me) like many of them use the same stock photo? You have to 'strategically' (LOL) trim the mat depending on several variables: coupe or convertible? Spare tire placement? (several possible hook locations) and maybe also year (shock placement). The trimming is not easy because (obviously) it is moulded (that's the whole point, right?) and you can't un-cut any mistakes.
Out of the box; the mat may seem to be longer than needed? I concluded the excess material was supposed to come up the tail panel (shielding the taillight wiring), with the assumption of aligning wheel well cutouts to the wheelhouses. This turned out to be the right assumption. It now seems obvious, but at the time I did mine I could not find it explained anywhere. This may be more readily apparent on a coupe (shocks being another reference point), but convertible has additional seat support and the mat goes up the support panel.
Once you determine where the tire-hook-hole needs to be; you can radius its corners using a brass compression fitting & a hammer on a wood block.
Probably will also need to cut out for the fuel filler inlet. The mat goes under the fuel filler shield, and around the trunk latch bracketry. This can be straightforward if original appearance is not a concern (otherwise another science project).
Convertible placement is especially tricky to get proper fitment around the cocktail shakers. Does this apply to you? (this becomes a considerably lengthier discussion).
Still another spin-off discussion (if points/originality are a concern) might address sound deadener underlayment. There is a great deal of discussion elsewhere on CRG (and other sites) on this topic.
I tried to make & use templates for the fuel filler & cocktail shakers, seemed like a great idea, but didn't work as well as I hoped. The molded mat contours made this tricky in practice. My results improved when I used "live" fitting in conjunction with "planned" (i.e. template) cuts, and making adjustments on-the-fly (if hadn't already cut something that i shouldn't have).
Hope this helps?