For me, I'll just leave my IC at home and bring my driver's
licence out. It also acts as an IC card so... there.
if you happen to get caught w/o yr driver's licence with you, i can
only think of 2 scenarios: either you can get them to escort u back
to your house to take yr licence and show them (unlikely) or, they
bring you back to the station and you have to get someone to bring
your licence to the station.
So, worth all that trouble? just bring your licence whenever you
are driving lah.