Nitrous installed!!!

yeah that would be safe since you got a m5 because if you spray off the line and accidently bog the car, your gonna lean out and boom.
you could do it from 1st of the line but its risky, i guess one of the disadvantages for a 5 speed if your just a weekend racer and a daily driver.
but yeah if its your daily drive and dont wanna risk it its very wise to spray at second
 
i bought it used on corral for 275. im going to college 1600+ miles away from home so i didnt really have any place to install it myself. basic install including plugs, lower timing, etc at the place i went to was $200. purge valve, bottle heater, switches in ash tray were extra.... bottom line if you wanted to go cheap you could add 100 rwhp for $250 or so if you're willing to install it yourself.