I just did a VIN Search & it came back as a Redline 2.0 Turbo. There does not seem to be much indicating the redline series other than the seats having a Red line.
If the VIN had an X in the 8th digit than yeah, it's a RL. Other than the seat embroidery, it didn't actually say "Red line" anywhere else on the car besides the floor mats. There is a small silver square badge with a red line through it next to the Sky badge on the rear left of the car. On the right rear there is a another badge that just says "turbo". Other than that there is no other badging differences between the two trims. The other differences between the base Sky and the RL are;
-2.0 LNF turbo engine
-limited slip differential
-Sport tuned suspension
-traction control with competition mode
-blacked out headlights
-open lower front grilles next to fog lights for the front brake cooling ducts
-silver painted faux fender vents
-160mph speedometer, with 6250 RPM redline, and white banded gauges
-turbo boost gauge in the DIC
-dual exhaust
-polished alloy wheels (chrome was optional on both trims)
-polished lower door inserts (optional on base)
-stainless metal pedal covers (optional on base)
-steering wheel audio controls (optional on base)