If you guys are all going to be obeying the speed limit on your drive down, may I suggest that you stock all your cars with loads of stimulants- coffee, kopi-ko, tongkat ali, ginseng, etc., etc..
It's going to be one looong (and potentially boring) drive...
Oh, and remember; don't stop at the Machap rest stop- there're loads of chicken (with wings and feathers) farms around the area and hence tons of flies that'll fly into your car the moment you open your door. No bird flu though. I hope.
The mid-point is Pagoh; it's downhill all the way from there.
Oh, and how to get to Geylang... hmmm... it's a little hard to give directions here, but suffice to say; it's towards "East Coast", NOT on the ECP (that's the name of the highway), but rather on the "old", "trunk road" kinda road that runs sorta parallel to the ECP. Get it? Oh, there's something called the Nicol Highway; that kinda leads to the East too. Aiyah, just look for East Coast Road and keep driving towards the sunrise. Yups, do that. Oh, and there's not just loving to be bought there- there's some really good beef kway teow, seafood, tau foo far and frog's leg porridge, for sale. Be aware of imitations- always go to the store/kopi-shop with the most people and the longest queues; cannot go wrong la.
If really, really, cannot find, then just park your car somewhere (open air carparks require you to buy "parking coupons" from 7-11s and petrol stations) and take a cab. Public transport in Singapore is blissful- except when it's raining and during rush hour.
Y'all have fun!