Fezza

I purchased a nice-looking Fiesta RS Turbo about a month ago and insured it as being a standard vehicle. Got a reasonable price with 2 years NCB.

Now, I have been shunted by an articulated lorry, and when the garage have come to collect my vehicle, the mechanic has said that the wheels are not standard (he believes tham to be from a mondeo), nor he believes are the lights and spoiler. He also says that it has been lowered, although I do not believe it has as I recently replaced the clutch and saw no aftermarket markings / stickers on the struts when the vehicle was up on stands.

Now, I am not asking 'how to get around' this issue, but I do want to ask the following...

How reasonable is it for an insurance company to expect a layperson to know whether a 20 year old car is factory specification, particularly if the said vehicle was purchased 'as a standard RST' in good faith? For example, would your mother know a fiesta with different wheels to standard if she was insuring the vehicle?

I am sure many people would not be able to identify whether, for example, a Cortina had the correct wheels for the model and year, nor do I think many people would know whether the RS1800i came with a tape player as standard and as such I consider it to be unreasonable to expect a layperson to know the specifications of every vehicle they may purchase incase they have an option that might not be factory. The wheels on my fiesta had the ford logo on them (embossed into the metal?), as does the spoiler, hence my believing that they were standard.

Based upon the above statement, would it be worth challenging the insurance company if they take issue with the allegedly non-standard parts?