Did you not read my answer?
The only remaining question then is your "550W" PSU. I think you are looking at around a 300W load, might be a touch more. Assuming your 550W PSU can do that on its 12V rails you should be good.
Just telling us a 550W doesn't tell us much about the PSU. The vehicle has four wheels. Is it good for freeway speeds and 30MPG?
Edited for spelling. Stupid spelling....