Should I tune/upgrade my Stealth cars, or use them as they are??

[Coldon66]

Was just wondering if it is wise to tune and upgrade the stealth cars, or are they at near optimum settings as they are?
What have others did with their Stealth cars?

??

 

[rubbaduck]

they are tuned, but not modded to the max, i.e. HP. They have Customisable tranny, suspensions, racing exhaust, but might not have full tubro, etc.

i found tuning could be quite personal, so IMO some tuning should be done to stealth car too.

 

[Cosbuster]

I always like my cars "stock" but that's just me.

 

[sheppard2jt]

Can anyone test this or confirm....
I had bought a Stage 3 engine upgrade for one of my stealths. If I delete this car from my garage will it reload itself next time I restart the game or if I re-download the DLC file? Just wondering if there is a way to go back to stock without starting the game over and don't have a USB stick available today to do a backup file and try it myself.