Driving Spanish Car - worried advice please

I am visiting my partner who lives in Spain for a long weekend and after a number of trips where I have ended up stranded up in the Campo whilst he works we have discussed me using his spanish car whilst he is in his works van etc.

I have never driven a spanish car before so I am just wondering if anyone has any helpul info/advise to help with the following questions, my fella has I have to say put the fear of god into me over the Guadia and their constant spot checks so I'd like to ensure I am prepared and fully legal.

1. - Is driving with my UK photo driving license enough if I am stoppped by the Guadia etc ?

2. - How do we ensure I am insured do we have to do that which my partners insurance I am guessing that my UK insuance wouldn't cover me.

3. - I have heard but this might be incorrect that in Spain its the vehicle that is insured and not the driver is that correct ?

4. - If I was pulled over by the Guadia do I need anything to show I haven't stolen the car as I of course wont be the registered owner ??

Many thanks for your time and responses in advance, I have tried to research this but haven't been able to find much out other than something to do with NIE of the driver of which I don't have as I am still in the throngs of thrashing out if a move to Spain is on the cards.

You need signed permission from the vehicle owner to drive the car. 

Your UK photo licence is perfectly acceptable.

The car is insured so anyone, barring age stipulations, is covered.

I'm somewhere between your stated locations in Spain, and I have to say, the only place I have ever seen checkpoints set up by the Guardia near me (in 17 years) is on the roundabout over the exit from the N340 into Torremolinos. (And touch wood, I've never been stopped) That's not to say there aren't many other regular spot checks - I'm just saying that perhaps you shouldn't worry too much about something that may never happen. I agree with the points mentioned by mariedav, but most importantly, drive in a manner that does not attract attention or give reason for anyone to stop you and you'll be fine. The worse that can happen is that you get stopped by a grumpy official who decides to give you an arbitrary fine simply because he's having a bad day, in which case I'm sure your partner will cough up - although it has to be said, it does sound a little like he doesn't really want you to drive his car! Or maybe he doesn't want you going off to the big city & bright lights without him!!

Thankyou for your responses very helpful and reassuring.  There does appear to be more of a Guadia presence over Torrox/Nerja as when I have been over and out and about in the car with him I've seen quite a few check points but that was late in the year and apparently funding for the Christmas Doo was low 😉

I will ensure I have the insurance documents and a letter from the other half along with my license should I venture out on girlie days out whilst he is slaving away all day.

thanks again.