update ko po kayo.. eto mga ginawa ko:
1.) Vinegar and newspaper (from other foreign car forums), cleaned the wiper blade and windshield na din, windshield wiper still wiggles (judders)
2.) Sandpaper (ung pino ginamit ko), dinaan ko sa wiper blade, windshield wiper still wiggles (judders)
3.) Sabi sa ibang forums, Carnauba Wax sa windshield, well, bumango ung windshield ko, gamit ko ung Mother's Carnauba Wax

, pero ganon pa din, wiper blade still has judders..
4.) Pede din daw WD40 sa wiper blades, windshield wiper still wiggles (judders)
5.) I checked on the angles of the wiper hand. (ung pinagkakabitan ng wiper blade, tama ba ang term? hehe) inayos ko ng konti, ganon pa din. so binalik ko sa dati, ganon pa din.
6.) Finally, napansin ko - ung wiper ko pala eh di lapat sa salamin, ung wiper blade may portion na nakaangat, particularly doon sa part na nagwiwiggle.. kakapagtaka lang, kasi Bosch AeroTwin ung wipers ko, and bago lang un. So I tried fixing it pero dahil sa rubber eh mukhang mas mapapasama lang ung porma ng blade. Sugod ako kagabi sa handyman and got myself another wiper blade, checked is thoroughly kung flat or hindi (hindi ko to nacheck dati) as akala ko it will perfectly fit itself kasi rubber nga.

Ayun. nung kinabit ko and turned it on, it wipes a lot better. I tried splashing some water while the blades are working and so far ok sya. Balitaan ko kayo kapag nasabak ito sa ulan ulit.