Wirral Motor Services
1 Tarran Way South
Tarran Industrial Estate
0151 677 4410
Have used them for almost a decade now, very very blunt and honest (ie. they tell you if there's a problem straight up, regardless of how big or small it is lol), recommended loads of my mates go there, all have come away happy, one mate took his RX8 for a clutch, £160, and they laughed when he told them some of the ridiculous quotes he'd be getting just because the engine is a rotary engine (ie. the clutch is the same as any other car). They also bill you fairly (ie. actual time it takes to do a job), so tend to come in a little less than their estimates most of the time.
Reliable bunch of fella's, have all been there since I've been going, is nice to see the same faces every time. Always happy to help, done a few things for me for free (took a car last year for diagnostics on a fuelling issue and it's been something simple [for instance bleed-off pipes were leaking so they replaced them as a matter of course] and they have not wanted to charge me anything). A lot of garages nowadays will charge you even to do a basic look at a car. Most things they do work out cheaper than other garages for, but not all (interior work tends to be higher than other places etc), so if price is an issue to you, then you may want to shop around, personally I only go to them (on the basis of trust), and the MGR specialist only when I really need to (once in a blue moon I guess lol).
Anyway, got my MOT done there last year no probs. £47, free retest if it failed, and they were not bothered whether I got any work done with them or arranged it myself.