[stovt001]

If it were my call, I'd give give Pontiac and Cadillac an Alpha based car that is about the size of a BMW 3 series. Trim the Pontiac at the same level of quality seen in the G8, and the Cadillac the same level we see in the new CTS. That gives Pontiac plenty of room to go upscale without stepping on Cadillacs toes. Move the Solstice coupe/targa/convertible and Sky convertible (haven't heard of any other variants yet) and you have plenty of volume right there.

Chevy already has 1 subcompact, 2 compacts, 1 mid-size sedan, 1 full-size sedan, 2 vans, 4 SUVs, 3 trucks, a sports car, and the upcoming Camaro and Volt. It needs to trim its lineup, not expand it. They also plan on giving both Chevy and Saturn the Zafira microvan from Opel, and Chevy yet another Lambda crossover. How insane is that? Doubling your lineup at the same time your market share is dropping?

As I see it, here is what they need to do:

Cadillac: Add in Alpha-based 3 series fighter. Same powertrain lineup at the CTS. Move the CTS up to compete against the 5 series, and move the STS up to compete against the 7 series. Refresh the SRX and XLR, maybe add in a Z4 competitor, stay the course with the V series, kill the DTS, and they're good.

Buick: Make it FWD/AWD, for people who want an elegant car and don't care as much about cutting edge performance. Give it a mid-size and full-size sedan, a hardtop 4 seat convertible (like the VW EOS), the Enclave, and a small CUV.

Saturn: Perfect as is. Basically it is for people who want a different dealership experience, so it has a good range of cars, everything from compacts to roadsters to sedans to a large CUV, so it is good. Keep expanding the Red Line trim and hybrid offerings and they are set. Maybe even add a wagon body style to the Aura

Saab: sell it. It is quirky and just really doesn't fit in with GM's direction. The cash would be good for GM, and new ownership can set Saab back on its traditional course.

Hummer: Add a Wrangler fighter and alternative fuel options (dual modes hybrids, bio-fuels, etc), keep everything off-road rated (don't pull a Jeep Compass for the love of God!) and they're set.

Pontiac. Add a targa body style to the Solstice, and move it over to a shortened Alpha platform. A small sport sedan and coupe on the alpha platform. Give the base and GT models the usual small high performance powertrains (Solstice GXP's 2.0 w/ 260hp and the 300 hp DI V6 sound about right) then have a special trim for the coupe only, drop a V8 under the hood and call it GTO. Duh. Give the G8 a name and wagon bodystyle, kill the G6, G5, Vibe, and Torrent, and call it a day.

GMC: Uplevel trucks all the way. Silverado, Yukon, Acadia, Canyon replacement, and the Ute. Simple and makes perfect sense.

Chevy:
Aveo, or Beat, Trax, or Groove replacement
Cobalt and HHR refreshed on the Delta platform. Should be good
Malibu on Epsilon II. Its off to a great start, so the next version should be even better. Give it a Wagon body style. Call it the Maxx.
Impala: Leave it FWD/AWD. Some people just want a big car, don't want an SUV, and don't care about performance. The G8 covers the people wanting a RWD full-size car, and FWD will make it easier to meet cafe. Just redesign it soon, make it bigger and just slightly higher quality than the Malibu, and you're good.
Camaro
Corvette
Silverado
Colorado replacement
Equinox
Zafira
Volt

See, minimal overlap, maximum platform sharing, and all your target markets are covered. Families, driving enthusiasts, young/budget oriented drivers, people who want an A to B comfortable commuter car, environmentalists, workers, and outdoor enthusiasts all have something they'd be interested in.

Also, the Canyon and Colorado will probably be axed in the next few years. This is probably due to low sales, but that is just because they don't stack up against the likes of the Tacoma. If they were redesigned to be really, really good, they could get a lot of people who need a truck but want more fuel efficiency.