It looks like housing expense rules weren’t the only things Senator Mike Duffy overlooked.

It looks like he forgot to renew the registration for his SUV.

The sticker on his licence plate shows it expired last month, but there’s no new sticker in its place.

On his way into the red chamber this afternoon, Duffy refused to answer questions from reporters.

Duffy is under an ethics investigation after paying back $90,000 in improper housing claims with a cheque from the prime minister’s chief of staff.

The RCMP is also examining the scandal.