If he's transfered the title into his name, you're off the hook. If he hasn't, make sure you send in you're notice of sale to the state DMV(however they do it in your state), or you'll be liable for any towing and or storage fees, should it get towed away, which will pile up way fast!

__________________
past MB rides:
'68 220D
'68 220D(another one)
'67 230
'84 SD
Current rides:
'06 Lexus RX330
'93 Ford F-250
'96 Corvette
'99 Polaris 700 RMK sled
2011 Polaris Assault
'86 Yamaha TT350(good 'ol thumper)