Retrofit TV Module in 2016 A7 4G

i was thinking of this but found it very expensive and intrusive for a gimmick that i would hardly use
im happy with my setup
chromecast 3rd gen ( 2nd hand) / hdmi-rca converter ( decent type) / rca to ami lead ( oe)
£20 / £17 / £52
can mirror my phone with internet / tv / whatever i choose at less than quarter of the price
 
ive tried ebay ami leads (usb is fine) but rca is terrible please avoid, i tried and went through 3 hdmi converters to realise it was the aftermarket lead providing the terrible quality video worse than a 30 year old vhs tape with the tracking dial way out of adjustment.... no joke