How to get DS to nap better when life with a toddler doesn't mix well with a routine

We've been having sleep issues with DS since 4months. He wakes a minimum of 4 times a night and this is a good night. Other nights it can be 7-8times.
Now, I know that sleep breeds sleep, so if he sleeps well during the day, he should sleep better at night. THe problem is, with a toddler, we cannot be home for every nap or else both the toddler and I would go insane. And DS does not sleep when we are out and about, at playgroup for instance.
I try to time a sleep with when we'll be in the car onroute somewhere, but this often means that instead of 2 good blocks of sleep, he'll quite often have 3 shorter blocks. I also try to put him down at home for at least one of his sleeps so that he can have a better sleep, but even then he may only go for about an hour.

So what did you do with your younger child when you have an older child's schedule to contend with?

I almost sent myself insane trying to fit DD3 sleeps into a routine around life with two others under 4. DD3 has never been a big sleeper and I used to spend hours bouncing her, rocking, slinging etc to try and get her to have the "right" amount of day sleep. I ended up cranky and teary, she'd be screaming and the other girls would be climbing the walls. So I just gave up and followed her lead. I gave her as much opportunity to sleep as possible but I didn't force it or stress over it. I guess I just went with the flow (this is really hard for a routine orientate person like myself). Eventually her sleeps got better (I am talking once she hit 12 months) and now at 16 months she sleeps through the night and has one 2 hour sleep in the day time. At around 10 months I stopped feeding her to sleep and using other gentle methods to put her down.

My post probably hasn't given you any great insight but I assure you in time this too shall pass. GL

Thanks Bek, I figured it would be one of those things that would get better in time! I was just worried that not having consitent naps was affecting his night sleep, but we've spent most of this week at home, so he's had good morning and arvo sleeps and it hasn't improved the night time at all so don't think I'll stress out about his naps now!