1st of all, dont use tinted car
just use the road passing by shell/mcd permyjaya on ur right, then emart on the left, then ILP on ur right. just go straight until u reach a crossroad. take right, then u'll reach the asean bridge. asean bridge toll is rm10 one way.
go straight until a small roundabout, u can see the malaysian immigration building, green colour. drive thru and hand them ur passport
next u'll reach brunei immigration. give them ur passport too. after that is brunei custom, u need to fill in a form. u need ur engine and chassis number for this. so make sure u come prepared. this information shud be in ur car insurance info, or user manual
after u fill in and submit the form, just follow the road. stick to the main road (u'll reach a somewhat Y junction, take right). after a bridge u will reach another toll, the pay is B$3 one way. then just go straighttt. look at the signs and u'll know when to get off to bandar. as whatman said, shud take about 1 hr
when u want to leave from bandar (try to leave before 7pm), just follow the signs to jerudong, since it'll lead u to the same highway u came in. dont go to Muara though, that's the opposite direction. thats y u shud leave at 7pm or 6.30pm just in case u get lost, u cant go past the border after 10pm. dun forget to keep B$3 and RM10 for tolls for the way back