I just sold a sports car and bought a truck. At the end of the day it depends on the girl, some girls love sports cars and couldn't give a rats about trucks, some girls are the other way around, some girls don't give a rats either way.
In the street, I definitely get more glances from girls in the truck, maybe it's just the sheer size of the thing but I'm more likely to get noticed. But I've met some girls that when they found out what I drove they go "ugh you drive a truck?" That never happened in the sports car. Take the girl for a drive down the beach or something in the truck and all of a sudden they don't mind it. Great for finding some isolated outdoor locations too
Guys that say that car doesn't matter, eh..... I've owned a fair few sports cars and it has opened the door a few times for me, I guess it's kind of a form of peacocking.