If it has a bulb-out indicator, it is definitively a Limited as the Bases don't have that feature and it would be something that has to be programed into the BCM and headlamp switch through DAS to enable. You can test the bulb out indicator quite easily by unplugging a reverse lamp, put it in reverse and wait a few seconds to see if a light bulb icon illuminates on the instrument cluster.

Some other differences:

Silver exterior accents - Limited - Yes, Base - No
Leather, power / heated seats - Limited - Yes, Base - No
Cloth, manual seats w/ adjustable headrests - Limited - No, Base - Yes
TPMS / Garage door opener - Limited - Yes, Base - No
Metal valve stems on wheels (TPMS senders) - Limited - Yes, Base - No
Rubber valve stems on wheels (No TPMS senders) Limited - No, Base - Yes
Infinity radio w/ silver ***** - Limited - Yes, Base - No
Non-Infinity radio w/ black ***** - Limited - No, Base - Yes
Amplifier under passenger floor board and subwoofers behind the seats - Limited - Yes, Base - No
Stainless inserts in sill plates - Limited - Yes, Base - No
Silver cigar lighter - Limited - Yes, Base - No
Black cigar lighter - Limited - No, Base - Yes
Flip-up cupholder - Limited - Yes, Base - No
Center console cubby - Limited - No, Base - Yes* Some people were able to get a cubby as a warranty replacement in their Limiteds.
Fog lamps - Limited - Yes, Base - No
Green fog lamp indicator light next to headlamp switch - Limited - Yes, Base - No
Silver airbox / engine cover - Limited - Yes, Base - No
Black airbox / engine cover - Limited - No, Base - Yes
Bulb-out warning indicator - Limited - Yes, Base - No

Hope this helps.