Here is another recommendation for Pete's services.
I'm not a Polo owner but have a VW Transporter T5 2009.
My driver's side window & central locking switches hadn't really functioned since Dec 2020. Maybe 2 sporadic periods of a few weeks where they did.
I chanced across Pete's post on this thread whilst searching the net (endlessly it seems for T5 issues) for insights on what the culprit could be. Countless times has my door card been off, under dash trim removed, switches checked, double checked, triple, motor removed & inspected, wire loom unravelled, wires inspected, multi meter out again & again, head frustratingly scratched, & foul language spewed from lips.
Nearly bought a replacement door loom. Then nearly bought a replacement motor off Ebay.
I messaged Pete just this Sat evening, & over this May bank holiday wknd, with his kind assistance via WhatsApp, between us we cracked the problem, & I now have fully functioning windows for first time.
I will say that Pete's services would be a great addition to the VW T4/T5 forum, as I can assure you, they'll be many a T5 owner that are in the same boat with these window motor issues.
Many thanks again Pete
Phil