Easy
1) Create a new user on your PS3.
2) Create a new PSN ID for that user.
3) Make this new ID a friend of your main ID
4) On your ID with the chrome paint, back up that save game to a USB
5) Once it's backed up gift the paint to your second account.
6) Now restore your save game from your main account so you get your paint chip back.
7) Log in as your second account and receive the gifted paint.
8) backup that save game and then gift the paint back to your main account.
9) Keep on doing this, but next time you can gift TWO paint chips at the same time, then next time FOUR. I think four is the limit you can send per day.
(Always remember to backup your save game before you gift anything and restore it straight after)
I have about 10 accounts all with different birthdays, each with a gift car ticket. I have managed to send each of these accounts a chrome chip.
Now each day I just log into each account and redeem the car gift, if it's one I like, I paint it chrome then I send the chrome car to myself and restore my saved game on the birthday account so I get my ticket and paint chip back ready for tomorrow.
I get ten chromed cars a day like this
It gets VERY tedious. I've spent more time messing about like this than actually racing today.