For section 84E of the Principal Act substitute —
(1) In this section—
"commencement day" means—
(a) in relation to a tier 1 relevant offence (other than an offence referred to in paragraph (b)), the commencement of Part 2 of the Road Safety Amendment (Hoon Driving) Act 2010 ;
(b) in relation to an offence against section 30(1), the commencement of Part 2 of the Road Safety and Other Acts (Vehicle Impoundment and Other Amendments) Act 2005 .
(2) For the purposes of the definition of tier 1 relevant offence , an offence is a second or subsequent offence only if the first offence was committed on or after the commencement day.".