Well you could try some Power Plus Fuel Fragrances. They come in Grape, Cherry, Bubble Gum, Cotton Candy, Pina Colada, Blueberry, Root Beer, Strawberry, Water Mellon, Rasberry, Cinnamon, Vanilla, Banana, Apple and Tangerine. I bought a bottle myself, but I misplaced it and can't find it now, I wanted to see how it works myself too.
http://www.summitracing.com/search/brand/power-plus-lubricants/product-line/power-plus-fuel-fragrances?autoview=SKU