The LCR isn't a cheap car to run. Get it remapped and drive it like it was intended, preferably with some softer high performance tyres and you'll be chewing through over £200 worth of fronts in ~8k (if you're lucky)
Fuel wise the LCR has a massive variation, driven gentley you can eek out mid thirties mpg, drive it hard and you'll get low twenties.
Tax, next year you'll be paying £400 a year. Oh and insurance, especially for a modded one isn't cheap.