This past weekend I went on a climbing/camping trip with my girlfriend. Bewteen climbing gear and camping gear, I figured we would have to take my 4runner, but she insisted that we at least try to see how much we could fit in the S's trunk. So I removed the jack holder (which wastes a lot of space) and started loading.
Our gear included:

A full trad rack (cams, tri cams, microcams & nuts)
12 trad quickdraws & spare slings
17 sport quickdraws
2 belay devices + 1 gri gri
3 60 meter ropes
2 harnesses
4 pairs climbing shoes
2 guidebooks
1 thermarest
1 Z rest pad
2 sleeping bags
1 tent (small 2 man)
2 headlamps
2 day packs
2 nalgene bottles
towel
crazy creek chair
clothes & toiletries for 2
Plus the jack, 1 qt of oil (just in case) & funnel.

Amazingly everything fit!


We did some excellent climbs and I also got in a bunch of great drives. Not bad.

 

I was amazed I could fit in 2 sets of golf clubs, though it's tricky to get it in. I might have bent the trunk thingy.