Or better yet try isopropol alcohol first. Small amount on an ear bud, wipe on and burnish or use a toothbrush to dig into panel lines.
Rember styrene is made from petrochemicals so I wouldn't use petrochemicals on it ... no-one expects them to eat into styrene, in fact those who do ... no, no, NO Cardinal Biggles, no-one expects the Spanish Paintstripquistion, our weapons are three, no four, our weapons are FOUR, turps, rocket fuel, JP1 or 6 for you blackbird drivers, and fanatical devotion to Mr Tamiya oooh ah ha! What be your name o Wizard? My name be Tim! Oh mighty Tim, takest thou thy holy oven cleaner and cast it at thy painted abomination and waitest thou twelve hours and the abominated paint, being nought in the Lords sight, shall snuff it. The number of thy counting is twelve, countest not to eleven unless thou countest to twelve, countest not to thirteen. Twenty is right out. Takest not the holy unsymmetrical dimethylhydrazine for thy oven cleaner for the Lord frowns on idolatry and hypergolic fuels ...