First of all, it is compulsory for all types of vehicle to register an AUTOPASS which called as vehicle passport before entering Singapore beside bring your original passport. For Singapore citizen, they CANNOT drive Malaysian cars into Singapore. It is forbidden by law in Singapore.You also can read the BROCHURE for AUTOPASS from Singapore LTA(land transport authority- JPJ likes Malaysia).
click here to download brochure
1) passport
2) touchNgo
3) white card (fill in form for details before entering Singapore).
white card sample