How to add relative geolocation functionality to an autonomous car

Ok, so I have an autonomous car, and I want to track it’s relative position to it’s origin, in an area of about 1 m2.
Can I use a wifi module for this? How precise will this be?
Or perhaps what module will be suitable
NB: Precision is quite a priority

Probably bluetooth signal strength triangulation is the easiest way.

Pozyx maybe.

Or place a grid of sensors in the specific area the robot moves on.

Bluetooth signal strength may work, if you can find a way to sufficiently precise measure this from at least three different points around the area.

wvmarle:
Pozyx maybe.

Or place a grid of sensors in the specific area the robot moves on.

Bluetooth signal strength may work, if you can find a way to sufficiently precise measure this from at least three different points around the area.

Just checked out Pozyx, way over cost budget. The project is quite small.

Well, it's not a trivial thing you're asking for - and I can tell you that even without you having defined the required precision.

Yeah I figured. Ok, thanks @IndianaTux and @wvmarle. I'll try and figure out bluetooth triangulation. Any suggestions on where I should start from? devices I could use?