Started the car this evening and let it idle a bit. White smoke came out for about 3 seconds upon startup and dark grey / black afterwards. Pretty heavy gas smell also. After about a minute or two, idle started going up and down. Went for a very short drive and at the first stop, the engine died. Exact same problem as on Sunday night.
I'll look into the fuel pump relay and potential vacuum leaks. Robby, I did look at the hoses going to/from the turbo and everything appears tight... Unfortunately, I don't think it's going to be that obvious! Still, thanks for the suggestion!
Any good reading suggestions regarding the fuel system on these cars?