I understand what you're saying, I would personally say anything around £300 is actually very good.
I know my costs, being 23, 2 fault claims, partial cost recovered on one and 3 points with only one years NCD means I'm paying £1500 on a Civic 2.2 Type S Gt!
The difference you are getting with the Golf and the Civic would be insurance group, from memory (I work in insurance for a living) the Golf is insurance group 6 while I know the Civic insurance group 10, this is in the old school system when it was out of 20 rather than 50!
I would hesitate a guess and say you have not disclosed your remap to the insurance company as I would expect it higher!
2 years ago I was paying just over £200.
I haven't disclosed the remap. If someone hits me then it's not relevant as far as I'm concerned. If I drive like a lunatic (I don't - I do too many miles) and crash then I probably wouldn't claim, either pay myself for the damages or break it and sell the parts.
I hate insurance, I only have it because it's legally required.
Sorry to digress, but let me tell you a story.
June last year my wife had an accident. She was driving home from work and a flat bed truck was approaching on the opposite side of the road. It was pretty windy and the truck had an unsecured load. A wooden pallet was blown off and came hurtling towards my wifes car, she did exactly the right thing in braking heavily but not trying to swerve to avoid it which could have caused her to hit something else. The pallet hit the front of the car, smashing the NSF headlight, scratching the bumber and denting the bonnet where it hit and bounced over the car. 2 cars following the truck were also damaged by other items coming loose. The truck carried on, it only stopped when chased by the 4x4 that was behind it that had it's windscreen smashed by something off the truck. It stopped anout 100 yards away. The truck driver became abusive claiming it was nothing to do with him. My wife then called the police who were not interested as no one was injured, but as the truck driver was refusing to give her any details she passed him her phone and he did eventually give his details to the police. Meanwhile a van decided to slow down and look at what was happening and a car behind hit the back of the van and another car hit the back of that car. The second car contained a woman and two kids and my wife, who had just been in accident herself, ended up calming down the woman and her kids. Due to the 2nd accident the police then arrived but refused to prosecute the driver of the flat bed truck and his unsecured/dangerous load. My wifes car was taken to her insurance companies recommended repairer. She had to fill in an injury form and she said she just had slight bruising off the seatbelt, no problem, no time off work. I'm not going to go into detail about the insurers recommended repairer, just to say after 4 attempts we got the insurance company to agree we could take it elsewhere who did a perfect job first time....
Several weeks later my wife had a letter saying she had to see a consultant regarding her injuries. She contacted them and said the slight bruising had completely gone. They wrote back insisting she see the consultant so she did. She told the consultant she had a bit of bruising, now gone, not a problem.
A few weeks later she had a letter saying the legal team were trying to get her £1,500 compensation for her injuries. She wrote back saying (I'm not joking here) she had no injury and didn't wan't compensation. They wrote back saying the other insurance company was contesting the £1,500 and were only offering £1,000. She wrote back saying I'll take the £1,000. They wrote back saying don't accept that, it's not enough. She phoned them and said I don't want compensation, they said try for £1,300. Honestly!! In the end she had to contact them in writing instructing them to accept the £1,000. We have now recieved a cheque for £1,000 because my wife had to brake heavily.
This is why my insurance is expensive. I'm sorry, I'm sure lots of you would have loved £1k but we didn't want it. What we wanted was for the truck driver to be prosecuted for an unsecure load but the police weren't interested.
I hate insurance companies. What amazes me is that they insist on personal injury claims. Sure;y they have as many against them as they instigate. No one wins.
Sorry about the rant