renault clio 1149 1.2 turbo dynamique tom - excessive steering wheel and column vibration - johnwj

Hello, I asked you a question to honest john back in May about my wife's Clio dynamique which we bought new in march this year having Px an i-music from renault cardiff. The sunroof was leaking and it took them 3 weeks with the car in the garage to sort it out by taking the whole sun roof out and re-doing the tubes that drain the water since they eventually found a crack present. There was also a loose nut inside the driver door panel which rattled going over small bumps and was removed, there were also some other 'issues'.... Anyway since new the steering column and wheel seemed to us to vibrate excessively when going over rumble strips before 30mph zones. You literally have to grab onto the steering wheel firmly and your hands and forearms vibrate when going over the strips. We mentioned this a few times and were put off with excuses...... Renault cardiff then had it in twice and told us what it was not ie brakes, suspension, discs, tracking were fine etc. They then said it was due to excessive pressure in the tyres...!!....A week later I checked the tyre pressure and found them all to be 5-6 Lbs under the manufacturer's recommended rating........so my wife had been driving on underinflated tyres as well....!!....This is a bit similar to a person being admitted to hospital with chest pain and having their heart checked out and told it is normal and then being told to go away but still with their chest pains ie the diagnosis of their problem not having been reached and the poor Patient still having the worry of their pains..... So we were not happy and renault UK got us to take it to renault Bridgend for a second opinion. On test drive the guys agreed immediately that things were 'not right'. They quickly found that the cause of the steering wheel and column vibration to be coming from a steering bracket welding issue. They have advised me this issue will be resolved under the manufacturer’s warranty. I have been told this is an 11 hour job. My wife has been given an enterprise car for a week to 10 days while all this is happening. We believe that if this all gets sorted that the car was never 'fit for purpose'.....what about the underseal rust proofing and re-sale value since we feel like going to another manufacturer.........where do we stand legally?........do you think we should refuse to pick it up even or are there grounds to ask for a new car?.....