Firebird
What is the appeal in a Corolla, Civic or Sentra, beyond being "Japanese"?
The Corolla, like its larger counterpart Camry, is the single most boring vehicle in its segment. It's slow and drives like a boat. Even the 180hp XRS is slower than its competitors.
The Civic is more composed, but is even slower unless you spring a few grand for the VTEC engine, which is still underpowered.
The Sentra... Christ man, the Sentra is probably the worst compact on the market. Unlike the Corolla and Civic which are half-decently put together, the Sentra uses shoddy materials throughout and build quality is barely a step above the old Cavalier and Sunfire.
Buddy, you seriously need to take a look at a Ford Focus. It and the Mazda3 are easily the best compacts (and, amusingly enough, they're both Ford products).
Corolla: Selling point of the Corollas are not "excitement". Toyotas have built serious reputation with those cars. When I think of "quality", I think of Corollas. Owners seems to love them as well.
Civics: I agree, they are gutless. However, they are also known for quality, fuel economy, built/finish. Hondas are one of the best handling economy cars IMO.
Sentra: I agree 100%. I don't like them(this coming from a Nissan fan).
Focus: Great value for your money(at least in the U.S.). I've never driven one, but they do get good MPG and looks decent. I still don't like the interior and liked the old exterior better, but still above average IMO.
Mazda 3s: You can call this a "Ford Product"(I'd give Mazda little more credit), but I like it way better than the Focuses. Better looking than Focus, in and out. Do Mazda build these themselves? I've been impressed with Mazda's quality in previous Proteges.
Firebird
And what's this crap about American midsizers being "heavy", having "horrible suspensions" and getting "terrible gas mileage". What the hell planet are YOU living on? Camry weighs 3108-3428lbs. Accord weighs 3020-3353lbs. Altima weighs 3044-3298lbs. Mazda6 weighs 3078-3287lbs. Malibu weighs 3174-3315lbs. Sebring weighs 3173-3228lbs. They're all pretty damn close.
"Horrible suspensions"? What!? Have you driven a Camry? You remember how you think a Buick drives? A Camry is exactly like that: soft, floaty ride on straightaways, then the softly-tuned shocks and springs make for a loss of composure and body roll as you round a corner (and some excessive understeer, depending on the corner).
Oh, and Transport Canada disagrees with your assessment of fuel economy:
Honda Accord (w/ 2.4L I4): 31/44
Chevrolet Malibu (w/ Ecotec): 29/43
Toyota Camry (w/ 2.4L I4): 28/44
Nissan Altima (w/ 2.5L I4): 29/41
Chevrolet Malibu (w/ 3500): 27/42
Pontiac G6: 27/42
Mazda6 I4: 28/40
Chrysler Sebring (w/ 2.4L I4): 27/39
Honda Accord (w/ 3.0L V6): 25/39
Buick Century: 24/39
Buick Allure (w/ 3800): 24/39
Ford Five Hundred (a large car, I know, but I'll include it anyway; w/ 6-spd. AT): 25/38
Toyota Camry (w/ 3.0L & 3.3L V6): 25/38
Nissan Altima (w/ 3.5L V6): 24/37
Ford Five Hundred (w/ CVT): 25/36
Chrysler Sebring (w/ 2.7L V6): 25/36
Chevrolet Epica: 24/36
Ford Taurus: 24/35
Buick Allure (w/ 3.6L VVT): 23/35
Mazda6 V6: 23/35
Seems to me they're all pretty close...
Customers don't want to buy "American" cars anyway. Like I said earlier:
Personally, I don't think anybody has bias against the "Big 3", because they are "American". Out of your list, only ones I wouldn't mind owning are: Accord, Altima, Mazda 6 and maybe Ford Five Hundred. Five Hundred is not a solid pick yet, because of the high price, but the design is starting to grow on me(I did hate it at first). I wouldn't buy any of the American cars in the list, including the Five Hundred and Pontiac G6. It's not because of their nationality, I'd just rather have an Accord or Mazda 6. I like their design, they handle well(IMO) and has above average quality. I might select Camry, if I was a family man. It looks "grown up". Last time I drove one was in the mid-late 90's, but I thought it drove smooth and handled well.
M5: What's a Safari?