I've copied this piece from a posting by one of our members on another website.
It sums the situation really well..
If anyone has any questions we, over at ACE would be happy to try an answer them
http://www.the-ace.org.uk/
Vehicle Registration Laws
There are 2 different organisations involved in this process.
The DVLA maintain the database that contains all the drivers and all the vehicles in the UK.
VOSA regulate the MOT test and perform roadside checks to improve road safety.
The “8 points” Registration System
To put this system into context, people must understand that you never own the registration document for a vehicle. It is purely on loan and they can remove the right to registration if a problem arises.
The “8 points” system is how they determine whether a car should retain its original registration. First they assign each major part of the car a set point score like this.
• chassis or body shell (body and chassis as one unit - monocoque ie direct replacement from the manufacturer) (original or new) = 5 points
• suspension = 2 points
• axles = 2 points
• transmission = 2 points
• steering assembly = 2 points
• engine = 1 point
To retain it’s original registration, the vehicle must score 8 or more points from this list. However this must always include the 5 points for the original UNMODIFIED monocoque shell/chassis. This doesn’t sound too bad, but say for a Mk2 Golf with a VR6 or 1.8T conversion, aftermarket suspension and a disk brake axle on the rear you’d have 7 points. The problem with this system is that if/when you take your car to be DVLA inspected it is down to the tester’s discretion on whether he allocates the points or not. The DVLA actually define each part as "the original part that the vehicle left the factory with". Obviously this is impossible to implement, as all the parts listed have at least a fair chance of being replaced throughout the life of a vehicle, not for modification but for warranty claims and servicing. For instance it's fair to say that if you go to a test with performance suspension parts fitted rather than OEM standard replacements you will lose those points.
What constitutes an Unmodified Monocoque?
Firstly it’s probably best to explain what a monocoque shell constitutes. From the DVLA definition:
“What constitutes a monocoque is that of how an OEM manufacturer would view it. The chassis or `cage` assembly and all components that form it, less any cosmetic panels or infills that make no structural consideration to the monocoque or its component parts.”
What this means
Your car WON’T need an IVA if you:
• Roll/Flare the wheel arches
• Fit different cosmetic panels (i.e. front end conversion, US/JDM body panels)
• Fit a roll cage (as long as the existing shell isn’t cut to fit it – holes through bulkhead to fit bracing bars to strut tops a no-no for instance)
• Fit/remove a sunroof as long as you don’t chop any strengthening members.
• Convert a car to a van – as you are adding to the existing structure.
Your car WILL need an IVA if you:
•C notch the chassis legs for driveshaft clearance
•Raise the strut tops
•Modify the floor or bulkhead
•Chop the roof off/convert to a pickup
•Modify any part of the monocoque
From reading the DVLA rules as long as you don’t add to the width or length of the vehicle it is fine to add strength to the monocoque. Therefore if you weld plate over the existing chassis legs and fill the holes in the bulkhead to smooth an engine bay you should be fine. However if you cut the bulkhead out and weld in a complete flat sheet section, or chop the chassis legs out and refabricate in box section you will be liable to IVA the vehicle.
How is this enforced?
These seem to be the main ways that people are caught in contravention of the rules:
• Changing body type on V5 – If you send off the V5 with the body type changed it will automatically flag up the car for an inspection.
• VOSA/Police Spot Check – If you are pulled into a VOSA/Police checkpoint they can pass information onto the DVLA if the vehicle is not what it says on the log book.
• Flagging up modified vehicles for inspection at shows and from magazine articles - keep your registration plates/chassis number (if visible to outside I.e. in windscreen) hidden if possible to make it more difficult.
There is a rumour flying around that they are going to give the MOT tester a “modified vehicle” button which he has to check if a modified vehicle goes for an MOT. If this is checked it will flag the vehicle up for inspection. However there is no evidence to say this is in the pipeline.
What happens if my car is flagged for inspection?
If your car is flagged for inspection you will be summoned to the nearest DVLA office. A trained inspector will then go over the car allocating points based on the above values. If the car passes the inspection the vehicle will retain its registration certificate. If the car doesn’t pass the inspection it’s registration certificate will be revoked, meaning that the car cannot be used on the road.
To re-register the vehicle it must pass through an IVA test.
The IVA test
The IVA test is a stringent inspection to register amateur built/radically altered vehicles. It was implemented as the old SVA test had no class for inspecting radically altered vehicles.
The test is too stringent to go into in a forum post. There is a PDF of the manual here
http://mcelroymotors...0may%202009.pdf
Most cars post mid 70s are type approved, and therefore in standard form should easily pass an IVA test. However in modified form it may be more difficult. There is definitely no way that a car running poke, stretched tyres or scrub line interference will pass. The best thing would be to print a copy of the manual off, buy a radius tool off ebay and go through each pointer making sure it will pass. It's laborious, but on the plus side it will give you an insight into how much though goes into designing a car to pass crash safety tests.
Costs
The costs of an IVA test are fairly high, around £450 (no vat), then £99 (no vat) for a re-test if you fail.
Chances of getting caught
Put simply, there is no way of knowing. There are thousands of cars that are still using their original registration number when they should be having an IVA test. You could drive around for 10 years and never get a whiff of an inspection, but on the other hand you could apply to swap onto a private plate, or an engine swap, and get flagged for inspection. It really is pot luck, but as time goes on there is a good chance they’ll find new ways to catch people out.
There is a current proposal that the DVLA local offices will be closed and their powers given to the Police/VOSA. Apart from the fact that it will mean the people doing the inspections will be more clued up on modified vehicles, I feel it could also give more ammunition to the police to clamp down on modified cars that whilst not necessarily illegal in basic terms (MOT, tax, insurance present) fall foul of the regulations.