Panoramic 300x900 print questions

[tarmac_chaser]

I've seen some 300x900mm panoramic prints in frames and they look really good.

What would be the best way of making a high quality image to be printed? The image needs to have a ratio of 3:1 but also be of a high enough resolution to fill the frame without looking bad.

Is making a panoramic photo with a series of shots the only way to do this? I presume one photo cropped won't provide good enough resolution?

 

[snapalot]

We have recently printed ten copies of this picture for a keen photographer in our area. He took it in four exposures and it was stitched in photoshop.

The final print size was 36"x8" plus the frame which made it 40"x12"