I just bought a 2005 RX 330, the next day my wife tells me she can hear a slight sound of air leaking from the back tire. When i got home that tire was 30 psi compared to 35psi like the rest of the tires. I filled the tire with air and didn't here anything. I'm thinking its a small leak and will fix it tomorrow. Today my wife took the car out to run an errand, and she tells me four lights are on in the car. 1) brake system warning light, 2) abs light 3) vsc light and the low pressure light.
do you think i bought a lemon or is it all related to that tire.

 

the only one tire related is the low pressure light... the other three may be critical...

if you can hear a tire leaking, it will lose more than 5 psi in an hour, nevertheless overnight it would be flat completely...

brake warning, abs and vsc can be something simple, or could be something costly... I would take it back to where you bought it immediately and see if they will do something for you...