Yes but..... the big but.... What if you live off your investments and they are making you money. You then finance a new vehicle with zero down and zero interest (or close to it). That $30k, $40K or $50k chunk you might have pulled from your investments to pay for said vehicle, could have been making you quite a bit of cash. Done properly, financing can actually save you on a vehicle purchase!!!
Now if the dealer is offering a big cash saving for a cash purchase, that might be different.... do the math first.
I paid cash for the last 2 bikes I bought. With the Rocket, if I remember correctly, it was 3.99% financing through Triumph for the full price of the bike. If I paid cash, I received a $4500 price reduction along with quite a few other perks. Went for the cash deal....