An RX8 is fine for carrying babies and children, two of my friends have RX8's, both with two children. Any advice?

Hello Everyone I often use these forums for help and I now have a problem of my own that I would like some advice on... I purchased an 07 Mazda RX8 at the end of July last year with a full service history, warranty and the backup of a Mazda dealer in North Wales, only had 35,000 miles on it and I paid Around £5000, plus a part exchange. Broke down on 3rd of December, repaired by my local Mazda dealer under warranty - they replace 3 coil packs that had failed. The prudent thing would have been to replace all 4 but the warranty didn't cover it and they didn't ask me. The car then developed a starting fault which progressed into probable engine bearing failure (took to a rotary engine specialist) and low compression. Another Mazda dealer looked at it and offered me £500 part exchange against a new Mazda2. I complained to everyone and they explained the Mazda warranty procedure, which involves me agreeing to pay for having the engine out and being shipped to a specialist where they strip the engine. Mazda then inspect it and confirm if they will pay or if I am liable for the costs. £1000 to have the engine out and inspected, then £3500 for re-con engine from Mazda. I agreed to this course of action, and the 2nd Mazda garage (who offered £500) did a visual inspection which revealed: Badly corroded discs all round (worn/pitted inner surfaces), 2 Broken/worn anti-roll bar drop links, failed catalytic converter, stuck caliper, incorrectly fitted oil filter (for a later model RX8!), poor performance, misfire at idle, rough running and a few other minor things. I phoned the selling garage to inform them I would like to send it back for repair, replacement or refund, they agreed to inspect the car but were clearly not happy and said it would be my responsibility to pay for transport back (car is un-drivable), consumer advice line agreed. So my plan is the following I have the car inspected to prove problems if it goes to court or they try to blame me (£175), send the car back to the original dealer (£225), requesting either a repair, replacement or refund in 14 days under the SOGA (time advised by consumer advice line) via recorded delivery, if they don't respond I will file a claim via the courts (small claims or moneyclaimonline?) and hope for the best! Please let me know if there is an further information you need to give some advice, any comments more than welcome! Really unhappy with this as it couldn't have come at a worse time - wife is 7 months pregnant and cannot get to work without a car. Can't afford to buy anything else either as took a loan to pay for the car (via debit card sadly). Thanks in advance Phil