I've nevere tacked on a spoiler to any car. Imo- it only serves to attract the wrong kind of attention. Like teenagers in clapped-out Civics, and worse- police officers.
I say save your $$ and buy WeatherTech mats that will ACTUALLY protect your floors and are functional. Maybe some RallyArmor flaps if you EVER drive on dirt or gravel. The paint will thank you.
There's my 2cents.