You could pick up a nice Miata for $5-7K then have $10K to mod it anyway you like.
Having said that the comfort/ride level of a modded Miata is a bit rough. They are great fun, British car look and feel with Japanese engineering/reliability.
However as much fun as
the tinymobile (my Miata) is to drive I fear my days of crawling in/out of a small sports car are coming to an end. I see more of a comfy grand touring coupe in my future
***cough*** 996 ***cough***