According to Indycar.com:
The No. 3 Team Penske car driven by Helio Castroneves was fined $35,000 and docked 15 entrant points for not complying Rule 22.214.171.124 (Underwing).
Helio had this to say via twitter:
The amazing win we had at Texas, specially when it did not make my car go faster!I! I stand 100% behind my@penskeracing they r the best!!!
— Helio Castroneves (@h3lio) June 12, 2013
Members may contest the imposition of the penalty pursuant to the procedures and timelines detailed in the protest and appeal sections of the IZOD IndyCar Series rulebook.