It won't be the case always. Earlier, up to 3 years meant not from the year of manufacture but from the date of first registration. You could bring down a vehicle up to 3 years from the date of first registration and cancellation certificate of this first registration was a must to include in the documents to import and produce to Customs. So even this 7 year thing too would mean slightly older vehicles than 2018 will be brought down if above documents can be submitted.
Excise duty, Luxury Tax maybe correct but VAT... VAT was not a component included in the motor vehicles tariff when we last imported vehicles. VAT was not paid, only Excise, Luxury (where applicable) and a VEL (Vehicle Entitlement Levy) of 15,000/- per vehicle.
We were using the right side of above equation for Excise Tax. Taking a Vitz as an example in 2018, excise duty = 996 x 1750 (1,743,000/-) this was what I paid in 2018 for my car. But now that 1750/- per cm3 is 2300/- in current tariff.
So there's no VAT paid earlier at the time of importation. But, if VAT becomes payable now, it's a whole different story.
VAT base is so ridiculous that it takes excise tax (e) in it too. VAT base would be much higher than the CIF and think of 18% of that base.
I think (just my opinion) that all those quoted prices may have been calculated using above Excise tax equation approximately (CIF + Excise Duty + Luxury Tax + VEL ) and because of uncertainty of VAT, they just say +VAT in advertisements. There will be a budget early next year and if they plan to go forward importing vehicles, there'd surely be revisions to current motor vehicles tariff. Then we can know for sure how they're gonna impose taxes on vehicles this time.