Tan Chong is not as sticky as C&C when it comes to servicing your car outside during the warranty period, so long as you can show evidence that it has been serviced according to schedule.
Autosaver and River View specialise in Nissan cars and they follow the maintence checklist according to Tan Chong's.
Their prices are generally 2/3 that of Tan Chong's, which translate to savings of approximately 30%.