Wrong coolant
 

Bought my 2011 V70 D3 2L 5 pot last August. Didn't realise the pink coolant it came with is not correct for this model. I get the "Coolant Low" warning about every 4 months.

What are the implications of running for at least a year with the pink stuff?

Not a lot, really. Dump it, Fill it with water, flush it out with an up to temp run, Twice, Dump that.
Stick a coolant system cleaner through if you want,
Then re-fill with correct coolant.

Basically 2 x water flush & dumps is enough to remove the wrong coolant from the system.

"Coolant low" implies a leak. Start checking pump, Rad connections, matrix etc...

As above, no implications at all, you can run it on pure water during summer if you liked. Just flush it a couple of times and refil with the long life stuff if you like. My D5 has the orange antifreeze in it and it runs fine.

You will have a leak if it’s disappearing and you need to top it up regularly.