Hi and welcome to the forum.
Despite the fact that you say there are no warning lights i would still have any error codes read using an OBDII reader.
I'm not a mechanic but i've never heard of too much oil in a car stopping it from turning over, i'm not saying it cannot be the cause though, in my experience too much oil usually results in lots of exhaust smoke as the excess is burnt off.
Sounds more likely to be an electrical issue to me, but you need to have any error codes read first, then it may point you in the right direction for diagnosis.

 

 

Thanks for replying, Wiggy. The mechanic that checked it over tested the electrics and said they were fine, but I'm not sure that he had the OBDII reader you mentioned. Luckily I have a nephew who works for MacLaren but his favourite engine is the eco boost! He and his dad are coming over to give me a second opinion.

 

its unlikely that you have mis-fueled it, since the filler system is designed to avoid this.

 

Thanks Gremlin. I just panicked and blamed myself