Car Tax Query

I have a friend who owns a 04 SUV. She has just realised that the Vehicle Lience Cert states that her SUV is registered as a commerical SUV. Since she purchased the SUV from a dealer who purchased in the north, she has been paying full tax for a passenger vehicle (€1300). My question is, if she goes to get the cert changed, is she liable for VRT + penalities or is the dealer who 1st brought the vehicle into the country but would appear to have not paid the VRT ????

moved from Taxation to Car & motoring related issues.

the vrt might have been paid. it used to be common to pay the vrt and then get a doe and tax it commercially while leaving the seats in. 254 instead of 1300 p.a. . the gov copped on however and stopped the testing centres from doe-ing jeeps unless the seats are gone and all seatbelt mounts etc are permanently welded up.