I've pontificated on this before, crappy interiors are a huge pet peeve of mine, especially when they completely let down the rest of the car. I won't buy something with an interior I don't like, and I have bought cars essentially because they felt so awesome to sit in.
Here's the thing - "light and airy" has NO place in my sports car. I don't want beige, cream, tan, white, sky blue, chrome, or anything along those lines in my car. A splash of colour is fine but the overall feel should be DARK, preferably black-based, and a little bit cramped. A good sports car shouldn't feel like you're sitting IN it, like a bathtub; you should feel like you're wearing it. Steering wheels should be three- or four-spoke, definitely not two, and have a thick rim, and the dials should be written in some bright colour like orange set against a black background. No whiteface.
That TR7 up above is a great example, surprisingly. It's got lots of red and crazy plaid, but it's properly dark, with a nice black base, and no-one would ever mistake it for their living room. You're in it for a reason.
Here's another example:
...it's my Starion. Despite a lot of '80s clunkyness, this one got it all right - black leather seats (this pic is a bit overexposed, but they're nice and black in person), black trim, orange dials, the shifter is close up next to the wheel, and it just feels really nice to sit in. (I just wish it didn't have those stupid electric seatbelts.) When I was looking for one of these I passed up what was probably a better car because I just couldn't see myself spending much time in its maroon-on-maroon cabin.
I don't like the interior of my Elan as much - it's not bad, but the grey looks like it was supposed to be black and faded, and the dashpad got warped in the sun and there are now some gaps between it and the fascia, which annoy me to no end. My eventual plan is to replace the dashpad and dye everything black.