I'm not against modding imports, there's just nothing like sitting in a straight pipe, stipped down, modded-up V8, hitting the gas, feeling the whole car shake like an earthquake, dropping the clutch, and spinning the tires through 4 gears while leaving enough molten rubber behind to form a speed bump a 1/4 mile long while flying across the line on only two wheels. Ooooooh yea!
The confusion over V8 muscle Vs. I4/6 and V6 import comes from people who think it's impressive that their $12,000 juiced Del Sol can beat a stock Mustang GT after a $5000 turbocharger, $800 exhaust transplant, flywheel and clutch upgrade, port and polish, etc. etc. If you drop as much money into the GT as you do in the Del Sol (actually... if you just boost it), the GT is right back to mopping the street with the Civic as if it wasn't even there. It all comes down to who has more money (and is a better driver), not so much what the car can really do.
Also, most mods don't INCREASE power... they just let the engine reach for its full potential. That is, the engine already was capable of producing that power - it just needed the opportunity (*chargers are a great example of that - their presence actually SUCKS power (most models).. but when the engine needs it, that force-feeding of fuel gives the engine the opportunity to do more with what it's already got - that's all - the charger doesn't actually give any POWER.. just opportunity). There's only so much a 4 or 6 cyl. can give.
That's why when you get away from strictly street-legals you almost always see the best track times posted by muscle cars. A fully modded, maxed-out and boosted Civic is NEVER going to come anywhere close to touching a fully pumped Z28 or Vette. IIRC, there was a drag Vette that can do 0-60 in 2 seconds or maybe even less. Supras and Skylines have a heck of a lot to give so they're a better match, but I've still never seen one that could beat a maxed out Vette. Civics, Eclipses, Talons, etc. can be more heavily modded and stay street legal - that's why you see them beat other street legal American cars. But muscle cars can be more heavily modded overall... they just can't be run on the street anymore.