Originally Posted by gpshumway
I understand what you're saying, but the Miata doesn't exactly have tons of luggage room. Switch to run-flat tires in a 2nd gen MR2 and the trunk + frunk space is easily greater than a Miata. Do a Cayman-like arrangement with luggage space above the engine and the situation improves more. Easy to do with a flat engine like Subaru uses.
I think the Miata has quite a bit of storage given its size, especially the NC. There are bins everywhere and a generous trunk. It all comes down to design: a third gen MR2 has virtually no storage, an Elise has a very good sized trunk (assuming you only put light things in it). But IMO MR is too risky and impractical to be used often.