Got a dashcam from my niece for Christmas.It comes with a 4 gb micro sd card.How long can a 4gb card record for?10 minute vid ,15,25,1 hr more?I realise it can be set for endless loop,just wondering so if I want to use it to record while atving or boating how long the vids would be?It doesn't say in the instructions and another question would be are these things up gradeable to say 32 or more gigs?New owner so im clueless about these things.