Removing sticky stuff on floorboards

In the process of bedlining my junk. I got all the thin metal off the floorboards and now im down to the stickiest crap i've ever seen. I've scraped as much as possible but i cant seem to get all of it off. Ive tried using a sanding wheel on my angle grinder but its just making a mess. Any tips/tricks to getting this shit off?

you talking about the seam filler? ive had good luck with a blow torch to cook it, then a flat putty knife. ive HEARD if you brush brake fluid on it, it'll help soften it up, but it sounds messy to me!

The thin tin/rubber backed heat guard? Heat a putty knife till it is just to warm to touch and it'll come right off the floor like sticky butter.
The seam sealer? Good Luck, a flap wheel is your best bet.

for the black rubbery stuff:

wirewheel/flapwheel just made a mess for me. i found its easier to remove while cold. i took a heatgun to it, but that just made it even more gooey. take something like a thin putty knife (i found that a cold chisel worked the best because it was easy to grasp and didnt bend under pressure) . just scape at it and try to keep it clumped together then use your fingers to pull it up. it adheres well to itself so have a ball of it in your fingers and use that to pick up the remaining spots. i then poured some xylene/xylol on it and wiped it up to get the rest. using xylene on large amounts of it makes a mess though and only degrades the top layers of it, so just apply it at the end

i didnt even bother with the seam filler

I got rid of the foil, sprayed it down with WD-40 and gave it a little while. The WD-40 dissolves the black rubbery stuff pretty well, from there its a scrub, soak & repeat sort of deal. Easy, though - and doesn't require a heat gun or torch.
The seam sealer I left alone and painted over, though the bedliner doesn't stick to it real well. I think a flap wheel on a grinder would be the best bet (as others have said)

Finally got most of it off with the putty knife. I didn't even think about the seam sealer. I'm thinking I'll just scuff it up real good and see what happens.

Wire wheel works best for me, on an angle grinder. Eats it right up - and flings it everywhere. All the flap wheel did was get clogged up.

Try brake cleaner yet? I personally believe that stuff will dissolve ANYTHING. Just don't use the angle grinder till it's evaporated and dissipated, because it's really flammable.

EDIT: Brake cleaner took all the road tar and undercoating gunk off of an AW4 inspection plate I had, just took a little scrubbing with a wire brush, would have come off without the scrubbing but went faster with.