Jeff Perkins 37, General Motors' newly appointed global design manager for advanced design, is responsible for the styling of the new Pontiac G6, the replacement for the Grand Am. He spoke to Staff Reporter Richard Truett.

The Cadillac CTS has a bold design, and it seems to be aging well in the market. Why?

It has great proportions and totally new surfacing. If you look back at some of the great designs of the past - the old Ferraris and Cord/Duesenbergs, even some of the old muscle cars - the cars you remember have clean designs and great proportions.

The CTS is the same thing. I think that's the key. Adding trendy details really dates a car. What we try to do as designers is create something that looks fresh today but also is a strong, timeless design.

What are the key proportions?

It's hard to say there's a golden rule. But dash-to-axle and overhangs are important. The long dash-to-axle really emphasizes a strong hood and gives the car a different profile. That's something most rear-wheel-drive cars focus on. We're seeing a trend away from cab-forward. A very short rear overhang and very long front overhang is a key dynamic proportion.

In the case of the G6, what we tried to do is stretch the wheelbase, and that does a few things for you. It gives you a much sleeker, cleaner stretched body side.

But it also dramatically reduces the rear overhang. With stretching the wheels, we also (increased the window area).

With the G6, I see a car that is bold and a bit classically styled at the same time. There are muscular haunches and an aggressive stance. There are curves as well as some sharp angles. What were you going for with the look of the G6?

If you see a car now like a Taurus or some cars from the 1980s or early '90s, they look very bulbous and jelly bean and unstructured.

If you go back to some of the domestic cars in the '70s, where they are all very straight-lined, it is very boring.

With the G6, it's the mix of the two that really creates a lot of surface tension. It's treating the car more like a piece of sculpture.

The Nissan Quest added some style to the usually boxy minivan. Why didn't it work?

You need to approach the minivan customer differently than you would a G6 or a CTS customer. The person who buys a minivan is almost buying an (appliance). You want it to look easy to use and intuitive and progressive. But you don't want it to look like you are trying too hard.

In my opinion, the Quest may have gone a little too far in terms of saying, "It's designed."