Gano katagal ang usual process ng transfer of ownership ng 2nd hand cars?

I know madaming documents ang kailangan lakarin sa LTO and RD, gets un. Pero ano ba usually timeline sa mga nakabili na rin dito ng 2nd hand car, ano ung timeline nyo from car viewing & inspection -> negotiation -> signing of DOS & other contracts -> maintenance/repairs/detailing -> car payment of buyer to seller -> on hand complete car documents -> buyer take home car and documents.

Bakit dito sa binibili kong 2nd hand parang ang tagal? Ito timeline namin:

1. car viewing & inspection w/ negotiation: September 1
2. Signing of DOS and contracts: September 3
3. Maintenance/repairs/detailing paid by buyer but si seller nag asikaso: September 4-5
4. Transfer of ownership in LTO: September 10
5. RD documents ongoing since: September 15

Until now hindi pa rin tapos, I'm starting to get worried.