Smaller, turbocharged V6.
In 1973, the Mustang 351cj weighed ~3680lbs 'dry' with 266hp/301ftlbs.
Today, a much faster V6 mustang weighs 3400lbs 'wet' with the much more powerful V8 GT weighing in at 3533lbs.
I think a Ford Mustang certainly qualifies as one of the most common production car of the last 40 years.
"You'll have to answer to the Coca-Cola company."
my educated guess is that they will keep both the 370z moniker and the current engine displacement. The current VQ makes plenty of power - the main complaints have been over NVH and fuel economy. I'm assuming Nissan is working to address these issues, most likely through the use of direct injection technology. I've also read that there are plans to shrink the z even further, so i'm assuming this will be accompanied by a drop in weight. A drop from 3250lbs to 3100lbs seems reasonable if they shrink the size of the car but continue to use a 3.7L v6. I already really like the current model 370z. i would be absolutely ecstatic if nissan released a ~3,100lbs, ~355hp 370z with a modified VQ37 with direct injection.
source: i like to troll around the interwebz for new car news.
From what I read, a slight increase in displacement wouldn't be a surprise. Nothing drastic, but possibly a bump to 3.8 to match the Genesis Coupe and a little more headroom for compression and HP. Direct injection for sure.