W221 Mercedes S65 AMG Dream To Temporary Nightmare

Good Day MBMedic, My nightmare involves my W221 S65 AMG 2007.I was told when I bought my dream that the main problem with this car was the coilpacks.80,000 Miles check engine light came on and went off in a week .About 6 months went by with the light going on and off so I scanned the car and got P0300 random cylinders misfiring along with P0301,P0311,P0302,P0303,P0309 confirmed fault codes along with09,07,10 Pending fault codes.Finding out the prince on replacement coil packs ,24 NGK Iridium Sparkplugs,and aVoltage Transformer had my dream put to sleep for a few months as I headhunt a resolution.Had a guy that refurbished coilpacks and replaced components in the voltage transformer and was helpful with his opinion but got lucky and found coilpacks brand new in the box at a dealership near San Francisco for $800 a side so I jumped on them.Finding coilpacks all the way up to $1800 per side and the Silicon Valley refurbish going for $699 per side it was a no brained to purchase the brand new dealership coilpacks.Now it’s on to the plugs and voltage transformer.Plugs are anywhere from $15 for Mercedes Star Branded to $7 ngk non Mercedes branded NGK Iridiums from summit but Me being Me Opted for the Mercedes Star Branded NGK’s from the same price friendly Cali Dealership for $9 a piece but the voltage transformer is another story.Apparrently they no longer produce the model new from temic A 000 150 02 58 Q1 and the brand new thin stock demands a premium over the remanufactured offerings.The Silicon Valley Guy replaces all the components with automotive grade diodes and industrial parts that fail from the heat making the original part a poor design from. The beginning.I am the type to buy brand new Factory not play the reman route but my question is if the design and internals of the brand new voltage transformer are the weak link so bad as they stopped manufacturing the part what is my best option.Reman is 400 and I think the Silicon Valley higher grade part replacement is more expensive. But less than the 800 needle in the haystack remaining voltage transformer stock.Any opinion would be Appreciated.Lastly I gassed up with a Seafoam treatment prior to the Sparkplug,Coilpack,Voltage Transformer Surgery and after sitting for months I Had a dead battery.Charged the starter battery started immediately but dash was flickering clock and Date wouldn’t hold and then all of a sudden I noticed the check engine light went off but a new ESP Unavailable See owners manual idiot light come on.I searched for a solution and found out that most likely it was the low battery and supposedly if I turn the steering wheel all the way to the left then all the way back to the right multiple times the esp should reset and the light go off.Its Been 2 days and still no check engine light but the esp unavailable still in the dash.I pulled the back panel to get to the main battery and put that battery on a charger .The electrics all seem to be brighter and functional but had a bear of a time setting time and date they kep going back to March 3rd ,2008 and the ESP Light Still on with check engine light off but motor still missing bad with a flat sounding exhaust.If I buy a new battery do I have to put a charger on the + and - to not have to reset anything or can I just swap out battery ?And Which Transformer do I shoot for brand new Mercedes in the box for $800 reman for $400 or Silicon Valley premium parts in the middle $?Whats the professional opinion on the check engine light going off and the esp light coming on due to low battery.Lastly with 9oz of Seafoam in the oil how soon do I change it? I always use Mobil 1 European formula what are your thoughts on the best oil and fuel additives like liquimoly ?Thanks For Reviewing my Novel Any and all help and advice will be greatly appreciated.Thanks Sincerely, MarcoMercedes Sent from Marco’s Red iPhoneHey