Installing new interior with a caveat

I've been driving my Sprite all these years with no carpet. Nearing the "end" of my rolling restoration project, I purchased a carpet kit over the winter intending to install it once the weather warms up. My issue, however, is that my car is a leaker. After only a few hundred miles I get oil coming up behind the crossmember on both the driver and passenger sides. I plan on attempting one of the scroll seal remedies out there, but if it were to fail again I wouldn't want oil ruining the interior.

Anyone come across this before? One of my thoughts was using Herculiner or something like that to try and seal up the floors. I'm used to sealing up my boat against water, but oil is a new one for me!

Edit: '65 Mk III Sprite

Did you use seal sealer? If not you will have leaks everywhere!
Rut

That's crazy. My car leaks like the Valdiz but it never makes it into the cockpit. I do not have a solution, but I admire the problem.

Also, if behind the cross member is where you are getting oil, perhaps the aft seal on the gear box is the source.

Good question about the seam sealer, I didn't consider that. I didn't do the body work, so I can't say for sure. I would presume not given the oil coming in.

I should be able to use some of the caulk-style sealer over the seams, yes? Without having to actually take apart the panels?

You should be able to get seam sealer, brush on and caulk type, from your auto paint or parts store.
Rut

Upon reading the subject line of this post I thought, "Oh great another custom tool I need to get." Then I thought, "Caveat... wait a minute..."