Mazda 6 Sport 2.3 petrol, spares or repair in London, Essex for sale

Regrettably having to sell our mazda 6, this is the top spec 2.3 sport model. In very good condition got the year with only minor marks on the body work, the interior is immaculate and as new with no marks at all. Currently sitting in RX8 17" alloys with the two rear tyres renewed last month with hankooks and have only covered about 300 miles. Had new disc and pads all round about 1000 miles ago (if that) and new catalytic converters about 2500 miles ago. Have a full electrical system strip and rebuild 8 months back to find a fault that wouldn't show up on diagnostics and that solved that issue. Still MOT'd for 6 months I think and tax up end of June. Has full Bose system, AC, cruise control, the works. Look up the spec of these, it's got everything. Now the bad bits and reason for selling, She broke down last week seemingly overheating as there was a lot of steam. However...... When started up to load on to the recovery truck it didn't sound good. The engine is very noisy and is knocking loudly and constantly almost sounds like the pistons hitting bare metal. I'm pretty sure the head gasket has also gone but that wouldn't account for the noise. It does still start and drive but I wouldn't drive it other than to load on to a truck/ trailor. Obviously I'm hoping to get as much as possible for it as need money for a replacement car. The two new tyres cost almost £300, the brakes were £450, the cats were £700, the list goes on. I think this is repairable if you know what your doing it just I don't have the time, inclination or knowledge to do so, Please email me with offers,