I purchased an approved used car from a franchised dealership with 29k miles on the clock and it appeared all preparation work had been completed. However, software issues appeared and the car was taken to my local dealership who fixed the problem but their free healthcheck video highlighted that all four wheels were out of alignment and had significant inner shoulder wear. The dealership I bought the car from eventually agreed to reimburse me the £80 charged to fix the alignment issues but refused point blank to change any tyres as they said they were all within standards with 3mm thread on all readings. At least one of the tyres was 5.5 years old so had done nearly 30,000 miles. The tyre shoulders were all bald on the full circumference but they were not interested and refused to accept any responsibility even though it was obvious their checklist of over 100 items had not been completed correctly (several other items were not done) The car is a 2020 Skoda Superb Hybrid so needs decent legal tyres to handle the extra weight on braking. My main question is are these tyres illegal or could they be subject to a fine?