Can't comment on this super peg product but I have used Aquaproof. It did a good job but I imagine both of these products are very similar. You can get this at BCF.
Went out last weekend and we got a mild sprinkle during pack-up, annoying but it allowed me to have a really good look at where the water was seeping in on my '03 TrackAbout. It seems that the seams along the front vertical canvas to floor/wall joint has become a bit dry. As many others have come across, I then remembered old mate saying he used a tarp nearly every trip.
Anyway, after a bit of drying and drenching it each morning (which seems to have fixed the seams), I've just used the same stuff as this, works a treat. As does the cheapo pressure sprayer, but I'll give this tip. Looking at the SDS for the stuff it's water soluble. So the best mix I've used thus far is 1:1, but I'm going to try 1.5:1 water/Aqua Proof next. Why? Because with straight goo, it's far too thick to get a decent spray pattern out, 0.5:1 same. 1:1 is pretty good but I'm figuring that a 1.5:1 is going to give a really fine mist, meaning you get less "splotchyness" and a really nice covering across your canvas. And yes, after the first application, water beads right off!
I realise this is a bit of a thread dig, but it's helped me out immeasurably, so the next person searching for "Leaking Canvas"should be able to find this solution fairly quickly (said the guy who's been on forums for far too long to actually believe it!!!