Fit under what recaros? The front seats? No. You might be able to do something crazy (cut out a bunch of the foam) on the back seats to get it to fit. Just put the first one in the trunk back against the far wall, and take out your spare tire kit. That first one barely fits behind my rear "seats" before blocking my rear window and there's a pretty decent bit of room back there.
That second one MAY be able to fit under those front seats, but it'd be a waste, don't get 8" subs when you have a huge trunk with plenty of space.
If weight is your concern you have plenty of options: A) Do what I already said. B) get a custom lightweight fiberglass enclosure built into the spare tire well, mine weighed 15 lbs over the spare tire/tools and sounded awesome. Or C) (this is the option I'm looking at now on the Porsche) Get a box, like the first one you have up there (which is actually the exact one I'm looking at, with the pioneer shallow sub) and build into it a quick disconnect so you can take it out easily whenever you're going racing. Easy as pie. Velcro the thing in the back so it won't slide but can still come out, and you're set.
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