Being that my biggest hobby is calligraphy, I've had to remove my share of ink from, well, everything. Depending on if it's water-based (rollerball) or oil-based (ballpoint), and how bulletproof the dyes are, it'll either be fairly easy or impossible. Try un-diluted IPA first, and if that doesn't help try acetone. Others can chime in on actual car-centered products, but those two usually handle any of the ink I spill on my wife's beautiful carpet…