My daughter’s 2002 vw cabrio automatic transmission will occasionally slip when starting from a standing stop. Rare and hard to reproduce.
Make sure the fluid level is correct. A slipping automatic transmission is foretelling it’s own future.
The first step normally, is to check the level, color, and odor of the transmission fluid.
However, IIRC, this VW may be one of those that does not readily permit checking of the fluid unless the car is up on a lift. But, if you can access a trans dipstick, then you need to check the fluid for the factors noted above.
When was the last time that the trans fluid was changed?
If the answer is either “never” or “I don’t recall”, then it is time.
Even if (as I suspect), VW does not list trans fluid changes in their maintenance schedule, the fact remains that this type of service should be done every 3 yrs/30k miles, whichever comes first. Those who do not do this can look forward to transmission failure anywhere from 90k miles to 130k miles.
If you decide to take the car to a transmission shop, do yourself a HUGE favor and avoid AAMCO, Lee Myles, Cottman, Mr. Transmission, and any other chain operation. Those joints will tell you that you need a rebuilt trans even if you don’t, and they will overcharge you for work that is often slipshod. Seek an independent trans shop that has been in business for at least 3 years.