I know what the OP meant, but while on topic of fuel additives, there's a video here: https://www.youtube.com/watch?v=UvS_D4_lF5U showing Lucasoil is pretty useless at preventing ethanol corrosion.

Stabil has been recommended here and is probably the better option. My fuel tank was like new with 5% ethanol petrol in it for 6 months, and then I added Stabil so I'll be interested to see what it looks like if I leave it another 3-6 months.

Welcome new member.  Scotty has commented a number of times on his channel against oil and fuel additives.  As I recall, he has mentioned running a high-PEA additive (eg, Techron) through maybe once, but otherwise don't add stuff.  Just use good gas  And as far as oil, just using good oil and filters and changing them frequently is enough.  

As far as the key fob, those things are very complex and fussy.  Hard to really "fix".  Maybe if there is a good locksmith near you who has all the necessary tools to analyze and fix them, they can check it out for you. 

(PS: we prefer if you enter each question in a separate post. Helps keep track of what has been answered and makes it easier for people in the future who have the same issues to search previous results)

Cheers!

You might want to search the board and look at the FAQ, the topic of additives has been discussed to death here.

Scotty recommends the ATS Carbon Clean fuel system cleaner and PEA-based additives such as Techron or Gumout. However, they should not be used on a regular basis, only if there is a problem where clogged injectors are known or suspected.

As far as what oil additives to use, the answer is NONE. Virtually all are useless snake oil. A good quality oil has everything that your engine needs.