I have a 2012 C30 T5 R design 6-speed manual. I just love this car. I plan to keep it forever and given that I don't drive much, it's relatively low mileage. I enjoy it's zippiness, especially in 2nd gear, where acceleration can feel like a rocket after a brief and flirtatious lag. Lately, I've been curious about getting the Polestar upgrade. I contacted my dealer, who said it's available for my car and would cost somewhere around $1,150. My question: Will I really notice an acceleration and speed difference? For those who have done the upgrade, do you think it was worth it? Are you glad you did it? Thank you!