Yes they are illegal
no there not
I rang my insurance to change cars to my ZS, they told me it's a 1.25 fiesta, I literally had to argue with them to change it, so don't believe everything your insurance company tells you.
Insurance companies are RARELY right tbh. It's a bit of a grey spot in the law tbh. Like when police say an exhaust is too loud, when in reality your exhaust isn't as loud as a Zonda now is it?
Although not actually illegal, you can break the law with them, as in making too much noise past 11pm. Easily land yourself a section 59 warning.
Section 59 = hero points no?
LOL