I contacted the nova team when i found out about it earlier in the year as i imported my van from europe about 2 years ago and its sat since. I have an email from them saying as it was imported before the nova date i dont need to apply for one until i am ready to register it, so basically everything will need a nova no matter when it came into the country, but if it came in to the uk before the date nova became compulsory you dont need to apply for one until you are ready to register it. I phoned because i saw the bit about a fine if you dont have a nova.
this bit lifted from the nova info page:
Notifying HMRC of vehicles brought into the UK
Vehicles brought permanently into the UK must be notified to HMRC within 14 days and any VAT due paid or accounted for. This means that you will not be able to register and license your vehicle(s) with DVLA or DVA until you have received confirmation from HMRC that your notification has been processed. The vehicle(s) must be for use in your business or onward sale by your business.
The quickest and easiest way to make your notification is online. By making an online notification you will usually receive an immediate acknowledgement from HMRC and calculation of any VAT due. You can notify up to 100 vehicles in 1 submission. If you're a VAT registered business notifying multiple vehicles of the same type you may be able to attach a spreadsheet to your online notification, or use the multiplication facility within the NOVA online service.
Find out more about telling HMRC you're importing multiple vehicles on the GOV.UK website (Opens new window)
You can also make your notification by completing a paper form (VAT NOVA1) and returning it to HMRC. You must phone the VAT Helpline to request a form VAT NOVA1.
A tax agent, adviser or a freight forwarding agent can make a notification on your behalf but if you are a VAT registered business then the agent must be registered as an online agent with HMRC
Information you need to notify a vehicle
To make a notification you need to have detailed information available including:
the make, model, engine size and body type of your vehicle
the Vehicle Identification Number (VIN)
the existing registration number of the vehicle (if applicable)
the value of the vehicle
mileage details
details of your supplier for vehicles from within the EU
the import entry number and the commodity code for vehicles from outside the EU
Please note that this list is not exhaustive and you may need additional information to make your notification.