for a 17-21 year old there are far bigger factors than insurance group ime. anything upto group 7 or 8 (before the system changed) is fine so long as its not your classic boy racer car that gets written off 10 a day! basically anything with a history of being written off by young drivers is going to be expensive!! for instance i found when i was younger that a 1.8 focus was cheaper to insure than a 1.1 saxo for me so the clio is not going to be the best for insurance i'm afraid!