2 warning triangles and hi-vis vests
As far as I'm aware you have to have
2 warning triangles and hi-vis vests.
I've heard that some car rental companies have them in the cars as part of their policy. But I've also booked a car in PP where I had to ask for them (and pay a deposit).
No harm sending off an e-mail and ask about their policy.
If they don't have it at the airport (or you forget to check - as I usually do in the urge to get to PP) and your rental car company has an office in PP you might be able to get it there.
see also AA website:
Driving requirements by country : AA touring tips. Local rules and advice for European countries - The AA
and
Compulsory equipment : compulsory equipment for driving in Europe - The AA
from Spain country info:
Compulsory equipment in Spain:
• Spare tyre – or tyre repair kit and the equipment to change the tyre
• Warning triangle - one warning triangle compulsory for foreign registered vehicles but carrying two is recommended as, in an accident/breakdown situation; local officials may impose a fine if only one is produced. Not required for two wheeled vehicles.
• Reflective jacket - The wearing of reflectorised jacket/waistcoat compulsory if driver and/or passenger(s) exits vehicle which is immobilised on the carriageway of all motorways and main or busy roads. However, it is not mandatory to carry a reflectorised jacket in the vehicle and Spanish police cannot fine a foreign motorist who does not carry one. Be aware as Car Hire Companies are not under legal obligation to supply them to persons hiring vehicles, so often don’t.