Board Thread:Game Discussion/@comment-26719180-20151104133142/@comment-26249703-20151104134126

Sorry to disappoint, but that's not currently possible. Time-Limited Events are only around for a while and are closed indefinitely, except for a few that have made it into the career, though that hasn't happened in a while.

Your best bet is to either buy them at 20% discount or progress past them and hope the Le Mans - Pursuit of Victory event is integrated into the career mode or that the cars you need come on sale. It's likely they will eventually be, as all 2014 LMP1s have been on sale at least once, but there's no guarantee.