This exploit has been first - presumably - posted on r/GTATrilogy. Full credit goes to redditor u/iamalegend091 who shared this! Thanks, man!
The intent is to exploit the sex appeal stat stack-up by purchasing the tats over and over again.
Here goes:
- Remove any clothing in any safe house (yep, just underwear & barefoot),
- Remove all tattoos in a nearest tattoo parlor,
- Get SuperGT* (after finishing driving school in San Fierro or elsewhere),
- Drive to Idlewood tattoo parlor** (Los Santos),
- Go inside butt-naked and purchase tattos for each possible body part, but...
- keep purchasing 4 back tattoos (there are 4 different ones) back and forth until you reach 50% sex appeal (don't get off the chair to look it up in in-game statistics, but rather look it up in Main Menu >> Stats >> Player).
- Go out and enter SuperGT (you may want to repair it in a pay'n'spray nearby to get full 50% from the car only - that is to say the car has to be in mint condition).
Pros:
You don't have to unlock Las Venturas or even San Fierro to get this.
You don't have to collect any oysters.
Your hairdo, fat or body muscle stats don't matter.
You don't need to purchase any late-game Didier Sachs clothes (or any clothes at all, heh).
What's more this works even if your sex appeal stat dropped to 0 for whatever reason.
Cons:
You need to spend some cash (no more than 8000 $ - this is my full tattoo expenditure, but it includes some purchases I made early in the game, so it's definitely less), but once the trophy pops a previous save can be loaded, so...
* - Or probably any other car that boosts sex appeal stat by 50%, such as Buffalo, ZR-350...
** - Not sure if it has to be Idlewood tattoo parlor, probably any will do provided it offers a selection of tats for the same body part, so you can stack it up.