This is the most fun a $25,000 car can give. The combination of a nearly perfect chassis and handling with a fairly stout motor is sublime. Another 30-40 rear wheel HP would make a big difference and would not upset the amazing balance this car has.
Handling, simplicity, no frills but not stripped down either.
Roll bar should be an option. Luckily aftermarket roll bars are plentiful, affordable, and very easy to install by anyone. A bit more power would be perfect. Easily fixed though ;) A radio that plays MP3's.